jeting for 450R carb on 400ex

[leasureryan]

Oh yeah....I also don't suggest anyone ride a 400 without one!.....lol

[leasureryan]

got dyno'd today.....seems the 190 was just a littlemuch for it...lost power up top. Bottom was jetted perfect. We jumped down to a 185 main....got better scores.....but tossed a 180 in, and gained 2.5 more horsepower than with the 190...and it pulled clear through with the 180. PERFECT!!! Gotta love the sniffer!

[zrpilot]

Originally posted by leasureryan
got dyno'd today.....seems the 190 was just a littlemuch for it...lost power up top. Bottom was jetted perfect. We jumped down to a 185 main....got better scores.....but tossed a 180 in, and gained 2.5 more horsepower than with the 190...and it pulled clear through with the 180. PERFECT!!! Gotta love the sniffer!

Dude,

Your killing me.... WHAT HP ##s DID IT PULL?????


PS: I was REALLY close with my original recommendations on jetting, wasn't I:devil: ????

LOL

[leasureryan]

How am I killing you? Is that a good thing or a bad thing?...lol

you were damn close brother....damn close!

190 main.....1st pull 31.18 rwhp

180 main.... 3rd pull 33.82 rwhp

nothing jaw droping....but hell....it's still a stock motor

Jetting is SOOOOOO important!

[redzoomer]

Originally posted by leasureryan
it's still a stock motor

Jetting is SOOOOOO important!

You're running a 180 with a 450 carb on a stock motor? I was running a 170 in mine and it felt like it was falling on it's face! Hmmmm...

[zrpilot]

Originally posted by redzoomer
You're running a 180 with a 450 carb on a stock motor? I was running a 170 in mine and it felt like it was falling on it's face! Hmmmm...
Here is some food for thought as I have wondered the same thing:

A larger carb will have less vacuum signal and require a larger jet to meter the same air fuel ratio.

[leasureryan]

Originally posted by redzoomer
You're running a 180 with a 450 carb on a stock motor? I was running a 170 in mine and it felt like it was falling on it's face! Hmmmm...

I started with a 168....and there was no way in hell it was going to work. It was so lean it would barely run. Tossed the 190 in it, threw it on the dyno, and worked our way down until we found the most power. I live in central Ohio...jetting must be way differant here. I can't help it that this quad accepts that much fuel.

hell....I was using a 168 in my 400ex carb. I was told to start near the same jetting....but that wasn't cutting it with the 450R carb.

[hypersnyper6947]

I gave up on trying to jet it myself, its going on the dyno tomorrow to be professionally jetted, i will let you guys know how it goes.

ZR thanks for the help before. I just want it running perfect now, i have been waiting sooo long to finally have it running great and woop up on my buddies on there 660's

[zrpilot]

Originally posted by hypersnyper6947

ZR thanks for the help before. I just want it running perfect now, i have been waiting sooo long to finally have it running great and woop up on my buddies on there 660's

You are welcome, glad to help.

Jetting on a dyno is a great way to get the jetting dialed in! Let us know the results.

OH BTW!!! VERY IMPORTANT detail. Bring a USB memory stick, floppy, or CDR disk when you go to the dyno. Ask them to put the native WinPEP files from your runs on the memory storage device. You can then download a trial version of the software and evaluate the runs however you please!!!

Keep us posted!

[hypersnyper6947]

ok so i got my numbers, i have to get my chart scanned so i can post it but my ex made 32.65 hp @ 6650 RPM and 30.82 Torque at 4771 RPM. I thought that was kinda of low for HP but the torque seems good. The guy said he just had a grizzly 660 in there on the dyno (2wd) and mine made around the same hp so...

[hypersnyper6947]

So i have a 165 main 50 pilot and the fuel screw is all the way out almost. The guy who jetted it said it falls off at the top end, but if he put a bigger main it would loose mid range power, but gain at the top. My max Hp hits at 4771 rpm, which is low. When i nail it in like 3rd it starts to stutter mid way through. If i slowly get through the throttle all the way to WOT then it does not stutter. I told him this and he said he would try to fix, free of charge of coarse. He said he thinks that it has an aftermarket needle in it, which flows more. So if i put the stock needle back in and then put a bigger main it should get rid of the mid range loss but still give me more fuel up top to stop the stuttering and give me the rest of my power.

What do you guys think?

Oh yea and it smokes a bit when i let off the throttle, whats with that?

[leasureryan]

so raise your main and drop the needle......wouldn't that make sense?

[hypersnyper6947]

Thats what im saying

[supernatural]

installed my 450 carb today and thanks to piecing together info and parts found on this thread it fired right up and seems to be jetted better than my stock carb was. it could also be that the carb is just that much better. my jets are as follows 180 main, 48 slow, needle in the stock postion and 2 1/4 turns out on the fuel screw and it ripped through all ranges of rpm without any problems. i'm at sea level (cape cod mass.) only thing i had to do was turn the idle screw about 1/4 turn from where it was and thats it. thank you again for all the help. and buy zrpilots adapter it made my life alot easier.

[BORY]

big problem guys i just moved to aruba and took my quad there since its legal to ride on the road but it is horrible to drive has no power i have a 212 main and a 52 pilot and if i gun the throttle it dies on its face i need more fuel but how much? its about 80s all the time in the direct heat. if i ease into the throttle it will be fine until i get up top and it starts to sputter again and fall on its face. it also seems like the more is running so hott also.

motor-416 (14:1) hotcam 2 ported yoshi full system 450r carb and k&n

what kinda jets and a/f screw do u guys have for me.

[TRXordie]

i finally got the 450 carb coming. 416, 11:1, stage 1 hot cam, HMF slip-on, no lid. from what ive read i think ill try a 180 main, 50 pilot, 4th notch and about 2 1/4 turns. any suggestions?

[curlyatju]

hey trxordie: keep us posted on your jetting specs. i got the same setup but with stage 2 cam and am trying to get some starting point for jetting. where you located whats your elevation. what jets did you have in your stock carb with this setup. thanks

[450 eater]

I have an 06 fcr on the way an i was wonderign if any 1 had a clue wher to start at i was thinking frrom all this info (190m- 50p) needle on the 4th noch from the top a/f 2 1/2 turns out..????

[Wheelie]

Originally posted by TRXordie
i finally got the 450 carb coming. 416, 11:1, stage 1 hot cam, HMF slip-on, no lid. from what ive read i think ill try a 180 main, 50 pilot, 4th notch and about 2 1/4 turns. any suggestions?

Stick with the stock R 48 pilot. Other than that it looks like a good start.

BORY--

Did you plug the hotstart? A 212 main is excessive for a 416.

[450 eater]

it came off of an eletric start (06) an im gessing its all redy blocked off?? an wher can i git Keihin jets kits at? or you can only bye the one by one



thks
-~travis

[Gagt518]

I recently just picked up a 450r Carb. Now i half to pick up a jet kit. My question is should i get a 450 jet kit or a 400ex kit? Thanks

[450 eater]

450jets....i just got a set of Keihin jets it worked out.its cheeper then giting a whole jet kit.


~travis

[Gagt518]

Originally posted by 450 eater
450jets....i just got a set of Keihin jets it worked out.its cheeper then giting a whole jet kit.


~travis

Where did you pick those up at?

[450 eater]

at hond power sports thay had them in stock..

[Gagt518]

Originally posted by 450 eater
at hond power sports thay had them in stock..

Is that a website or a local shop?

[trx400 rider]

where did you get the stock 450 carb.

[450 eater]

ok so i have a 06 fcr 450r carb an i cant git the jeting right at all so i took it to my frend hes is a tec at honda an we try the 170m an the 50p but it was runing relly ruff poping thru the air box.. but running good on top end.so he put a biger p jet in it an he endnt up with a 65p and 170m with the a/f at 4 turns but he told me that it needs a bigger p jet..i dont think it dus. i think its too big anyways..my spark plug is relly black so i think its rich i tryed a 165m but still no beter.it want idle more then 45sec


~travis

[zrpilot]

Originally posted by 450 eater
ok so i have a 06 fcr 450r carb an i cant git the jeting right at all so i took it to my frend hes is a tec at honda an we try the 170m an the 50p but it was runing relly ruff poping thru the air box.. but running good on top end.so he put a biger p jet in it an he endnt up with a 65p and 170m with the a/f at 4 turns but he told me that it needs a bigger p jet..i dont think it dus. i think its too big anyways..my spark plug is relly black so i think its rich i tryed a 165m but still no beter.it want idle more then 45sec


~travis

Sounds like your tech friend needs some more training. Just kidding... Sorry for your troubles. The '06 FCR has not been used by many people. Only one that I know of and he also had jetting challenges.

Good luck, wish I could help.

[450 eater]

ok thks. i dont think he know what he is talking about im going to try some small jets.im trying to git it to run len then go from ther no mater what jet i use its rich?any tips will help


~Travis

[QUADSQUAD7]

I'm building a 2001 400ex for a guy and I'm doing the 450r carb conversion. The carb has a hot start that I've blocked off. The carb is jetted with a 48pilot, 180main, and the needle clip 3rd from the top(unsure if its the stock needle). I have adjusted the a/f screw every way in and out but can't get the thing to run right. Won't idle and pops and cracks.
The only motor work is a port and polish job. Has a full custom built exhaust. The thing is running very lean.
Any help would be greatly appreciated.

[Zeb400EX]

I got a 450r carb that has a HRC needle in it. I am wondering if anyone has use this needle with a 400ex? I already got a new stock needle too. If you compare the two, the HRC is thinner than the stock. I might see if the HRC needle works after I get the jetting right with the stock one

[hypersnyper6947]

Ok so i cant floor it, this is annoying, if i just gun it, it cuts out bad, if i slowly gun it, it will still cut out just not as quickly. It works great up to about half throttle, I assume this means i need a bigger main any suggestions would be great.

Thanks

[jeepnhal]

ok im getting a 04 450r carb any day in the mail.what jetting should i try?i never tuned or jetted a carb sooo.
stock motor
airbox lid on
uni filter
white brothers e-2 series with 1 or 2 discs in place
91 octane
oh its an 01 400ex

[hypersnyper6947]

I finally got mine about right, my mods are in my signature, i have 48 pilot needle on the 4th notch from the top, and a 178 main. Im not sure where my fuel screw is. hope this helps

[zrpilot]

Originally posted by hypersnyper6947
I finally got mine about right, my mods are in my signature, i have 48 pilot needle on the 4th notch from the top, and a 178 main. Im not sure where my fuel screw is. hope this helps How do you like ALL that ZR power? :D :D :D :D :D :D

40HP feels pretty good now doesn't it!

[hypersnyper6947]

Originally posted by zrpilot
How do you like ALL that ZR power? :D :D :D :D :D :D

40HP feels pretty good now doesn't it!

Oh yea it pulls like a mule....:D

I couldn't be happier, i cant wait to mop up some 450s and my buddies on there 660s

[bbender85]

ok, just got my EX going w/ a non-FCR:

- 426, 11:1
- stage II hotcam
- T4 slip-on
- k&n w/ prefilter, no lid custom box
- intake spacer

- 195 k main
- 52 k pilot
- screw 2 3/4 turns out

watch this video:

http://s154.photobucket.com/albums/s248/bbender85/quad/?action=view&current=MOV04649.flv

notice the backfiring, excessive time to come back to idle (i was just touching the throttle quickly), and the self-racing at the end........ whats the deal??

[vanhecke28]

I have a 400ex with a 06 450r carb white brothers exhaust, stage 2 hot cam, advanced timing key, open air box and kn air filter with outer wears. live in minnesota need some jetting information on the carb

Originally posted by bbender85
ok, just got my EX going w/ a non-FCR:

- 426, 11:1
- stage II hotcam
- T4 slip-on
- k&n w/ prefilter, no lid custom box
- intake spacer

- 195 k main
- 52 k pilot
- screw 2 3/4 turns out

watch this video:

http://s154.photobucket.com/albums/s248/bbender85/quad/?action=view&current=MOV04649.flv

notice the backfiring, excessive time to come back to idle (i was just touching the throttle quickly), and the self-racing at the end........ whats the deal??

i want to say your lean on the pilot

[bbender85]

Originally posted by FlewByU352
i want to say your lean on the pilot

come to find out i sealed the hotstart port up real good.... but not the passages it connects. sealed those and i was good........ so you're right! was getting waay to much air.

[3or4HONDA]

Originally posted by bbender85
come to find out i sealed the hotstart port up real good.... but not the passages it connects. sealed those and i was good........ so you're right! was getting waay to much air.

how did you seal the passages? i was gonna use rtv and just fill the hole with the plunger and everything removed until it came back out the top is this what you did?

[bbender85]

i put some epoxy down in the port and jammed it down with a tubular piece of plastic i happened to have sitting on my bench that fit perfectly, which squished the epoxy thru the passageways both ways a little, then i also put some epoxy in the end of the passageway on the motor side of the carb, and made sure it was flush with the bore of the carb, as to not disrupt flow.

[3or4HONDA]

idle is kinda all over the board....any suggestions....

thanks

[BigLuke]

Originally posted by 3or4HONDA
idle is kinda all over the board....any suggestions....

thanks

Vaccum leak possibly.

[fireems519]

any idea where i can find conversion chart for dyno and kiene?

[hypersnyper6947]

Search in the search box for it im pretty sure i have seen it on here before but dont remember exactly where.

[TRXordie]

i put this thing on and got an instant improvement! spent an afternoon gettin her dialed in. my problem is idle. no matter what i do it idles fast. im running a 416, 11:1, stage 1 cam, HMF slip on. Ive got a k190 for the main, k54 pilot, 2 1/4 turns on the screw, and in the middle with the needle. i cant find any air leaks, Ive tried the idle screw... i can get it to idle faster but not slower. it pulls like a champ just idles high. anybody have any suggestions??

[bbender85]

are you using a 400 cable or a 450?

[TRXordie]

450 cable... ive tried adjusting that as well.

[bbender85]

are you using the hotsart cable? if not, is the port AND the passageway plugged good? that was my problem.

[TRXordie]

i just cut the wires for now so i wouldnt have to worry about it leaking during the tuning process.

[smokindw]

I,m switching my old stock 400ex carb for the 450r carb, now i have already got a dynojet kit in my stock carb and it runs real good. Can i just put the needles and jets from my stock carb (which r the dyno jets kit) into the new 450r carb or will i have to buy a new jet kit??

^^ Im with this guy, On JetsRus.com, they have 450r jets and 400ex jets.. which would you buy? and can you just clip the hot start cable and ziptie it out of sight?

[zrpilot]

Originally posted by smokindw
I,m switching my old stock 400ex carb for the 450r carb, now i have already got a dynojet kit in my stock carb and it runs real good. Can i just put the needles and jets from my stock carb (which r the dyno jets kit) into the new 450r carb or will i have to buy a new jet kit??
smokindw,

you will need new jets, but I would not buy a "jet kit". Rather you will probably need the stock needle, a 50 and 52 pilot and some main depending on your setup.

[zrpilot]

Originally posted by SuicideMFNdoors
^^ Im with this guy, On JetsRus.com, they have 450r jets and 400ex jets.. which would you buy? and can you just clip the hot start cable and ziptie it out of sight?

See this (my 450R carb install) (http://www.exriders.com/vbb/showthread.php?s=&threadid=314423) for help, but yes simply remove the hot start, but make sure it is COMPLETELY sealed off. If upgraders have problems, most of the time it is because the hot start is NOT completely sealed off.

Oh BTW, see post above for jetting answers. Also ask, their are a LOT of others that (me as well :) ) that can help with this.

Originally posted by zrpilot
See this (my 450R carb install) (http://www.exriders.com/vbb/showthread.php?s=&threadid=314423) for help, but yes simply remove the hot start, but make sure it is COMPLETELY sealed off. If upgraders have problems, most of the time it is because the hot start is NOT completely sealed off.


What is the correct way to seal the hot start off (what do you use etc.). This is really the only thing I'm unclear about.

Also Zrpilot, do you still have adapters available?

[zrpilot]

Originally posted by SuicideMFNdoors
What is the correct way to seal the hot start off (what do you use etc.). This is really the only thing I'm unclear about.

Also Zrpilot, do you still have adapters available?
The correct way to seal off the hot start is simply remove the cable that leads to it and leave the plunger, springs and cap on it it. I simply used some black RTV to seall off the cable cap connection to ensure no dirt would enter the hot satrat plunger.

Yes I do have some left... PM sent.

zrpilot

[smokindw]

have a 2006 TRX 400EX, I have an BIG GUN REV BOX
HMF IRONMAN SLIP-ON CARBON
FMF powerbomb header
RENTHAL FRONT SPROCKET 13T
RENTHAL REAR SPROCKET 37T
RENTHAL R3-2 520 O-RING CHAIN, and K&N air filter with the K&N powerlid,Stage 2 hotcams camshart, and the wiseco 440 big bore kit at 12.5-1 compression ratio.
I just installed the 2004 450r carb, and when i try to start it i gotta pump the gas a few times and when it finally starts it is over-revving really bad and if i dont continue 2 giv it gas it stalls!! Please help me with what size needle i need which clip i should be on and should i buy a jet kit for a 450r or a 400ex and which brand is the best 2 use and if i need to be doing anything else ?? Also there is an open hole on the top front of the carb and 2 different wires that are hanging that look like they should be plugged into something, i know that im a neebie but i really need som help please!!!!

[bbender85]

..Also there is an open hole on the top front of the carb ..

haha, you need to read through the sticky. this must be plugged, and well.

[smokindw]

that is the hot start

[zrpilot]

Originally posted by smokindw
that is the hot start
Sounds like the hot start plunger might be missing

As far as jets go here is a START:
Main: 180-185
stock needle on the 4th notch from the top
pilot:50-52

If you can please take some pictures of the top of the carb as it is intalled on the motor.

zrpilot

[tom416ex]

okay so here is my question. I bought a 450r carb for my 400ex. It does not have the hot start. Can i throw so jb waterweld in there to seal it and possibly put a bolt in there big enough to block the hole on the top? I am hoping that if i drop the waterweld in there, it seals the little hole that is at the bottom of the hot start. Is this something i can do, or does anyone have a good idea? I went to home depot and 3 auto stores and they cant do a d**m thing for me except recommend that I just seal the entire thing top to bottom with waterweld or some kind of sealent?

[bbender85]

yep, i tried finding a plug too; go figure, it's a special size thread.

anyways, i just sealed mine with epoxy, making SURE to seal the passageway that the port connects; i epoxied down in the bottom of the hole, and on the one end of the port (where it dumps into the motor side, right on the bore)

[tom416ex]

so jst epoxy and fill the hole and your good? U didnt put any kind of cover or seal or anything in it?

[bbender85]

i had a spare plastic push-pin fastener (the ones used to hold all the plastics together) and used the push part of it as a "plug"; after i epoxied the bottom of the port, i set that plastic piece on the port with some more epoxy.

[QuadJunkies]

My quad seems to be a moody girl this year on jetting... pops abit ,never done that before, so next weekend when we Dyno tune my Daughters SuzukiLTR, we will be throwing mine on the Dyno as well. Im kinda curious to see how much difference it will have after we are done.

[BassHunter0123]

i just installed my 450 carb today and it wont start or even act like it wants to start. the guy i got it off of says the jetting was 50/185. even if the jetting is off a little it, should it still start up atleast? any thoughts?

[tom416ex]

i put my 450r carb on my 400 today also. I have a 172 main with a 50 pilot. It starts right up no problem, idels great, just as soon as i hit the throttle it dies right away! Im thinking its getting toooooo much fuel and i have to go down on the main? What do you guys think? Any info would be great! BTW, i have a stage 1 cam, 416 kit, slip on and a k&n filter with the lid on....

[BassHunter0123]

got my carb today has a 50 pilot and 185 main. it seems the engine temps are higher than normal. and i am getting some backfiring on decel. any suggestions on which way to go with the jets

[zrpilot]

Originally posted by tom416ex
i put my 450r carb on my 400 today also. I have a 172 main with a 50 pilot. It starts right up no problem, idels great, just as soon as i hit the throttle it dies right away! Im thinking its getting toooooo much fuel and i have to go down on the main? What do you guys think? Any info would be great! BTW, i have a stage 1 cam, 416 kit, slip on and a k&n filter with the lid on....

Does it act like while riding or just at a stand still in neutral?

Is it a new or used carb?
Is the Accel pump working?
Where is the needle set at?
Did you adjust the Idle mixture?
Lastly, I think that a smaller main MIGHT be needed if running with lid on, but it should not affect things until 3/4 or more of throttle.

zrpilot

[zrpilot]

Originally posted by BassHunter0123
got my carb today has a 50 pilot and 185 main. it seems the engine temps are higher than normal. and i am getting some backfiring on decel. any suggestions on which way to go with the jets

Running hot is tough to judge... how does it run? If it were SO lean as to create a hot enginee I think it would run badly.

As far as backfiring on decel, have you adjusted the idle screw? If not turn it out in increments of 1/2 turn and see if it gets better.

Did you solve the float issue? You have to remember that float level is CRITICAL to proper fuel metering on these carbs!

[Wheelie]

I think a lot of the problems people are having with these carbs are related to the hotstart. A stock/lightly modded EX shouldn't be lean on the pilot circuit with a 48 or 50 pilot installed.

IMO--The only way to properly plug the hot start is too buy a hot start plunger. If anything else is used, problems are likely to occur.

[tom416ex]

it was at idle, as soon as i snap the throttle it bogs and shuts off. It is a used carb i bought from someone here on the forum. I didnt really touch the idle mixture or the needle yet. I was thinking of going down to a 168 or soemthing like that for the main.

[Wheelie]

Are you revving it in neutral? If so, that is NOT a proper indication of jetting. A machine that is jetting properly may still die if the throttle is 'snapped' open in neutral.

Tune the machine under a load, not in neutral.

[tom416ex]

yeah, i wasnt riding it, i dint even bother. I will try it again on wed. when i go to finish it and let you know whats going on.

[zrpilot]

Originally posted by Wheelie
I think a lot of the problems people are having with these carbs are related to the hotstart. A stock/lightly modded EX shouldn't be lean on the pilot circuit with a 48 or 50 pilot installed.

IMO--The only way to properly plug the hot start is too buy a hot start plunger. If anything else is used, problems are likely to occur.

THANK YOU !!!


X2 X2!!!

[zrpilot]

Originally posted by Wheelie
Are you revving it in neutral? If so, that is NOT a proper indication of jetting. A machine that is jetting properly may still die if the throttle is 'snapped' open in neutral.

Tune the machine under a load, not in neutral.

Cha Ching!!!

Again Wheelie your right on with my thinking!!!

Nice analysis!!

[smokindw]

have a 2006 TRX 400EX, I have an BIG GUN REV BOX
HMF IRONMAN SLIP-ON CARBON
FMF powerbomb header
RENTHAL FRONT SPROCKET 13T
RENTHAL REAR SPROCKET 37T
RENTHAL R3-2 520 O-RING CHAIN, and K&N air filter with the K&N powerlid,Stage 2 hotcams camshart, and the wiseco 440 big bore kit at 12.5-1 compression ratio.
im gettin a dynojet kit that comes with 1 Main Jet DJ104
1 Main Jet DJ108
1 Main Jet DJ112
1 Main Jet DJ116
1 Main Jet DJ120
1 Main Jet DJ155
1 Main Jet DJ160
1 Main Jet DJ165
1 Main Jet DJ170
1 Main Jet DJ175
1 Main Jet DJ180
1 Fuel Needles DNO912
1 Main Air Jet Plug DCO500
1 Air Jet Plug Tool DT001
1 Adjusting Washer DW0001
1 E-Clips DE0001
1 Main Jet Adapter DJA001
Which of these do i need to use?? right now i have the 2004 450r needle on the 4th clip down with everything else on stock--pilot and so on, the f/a screw 2-1/2 turns out. when i give it fuul throttle it bogs out and trys to die untill i let off the gas. what is wrong and what do i need to be doing?? thanks 4 any input!1

[zrpilot]

Originally posted by smokindw
have a 2006 TRX 400EX, I have an BIG GUN REV BOX
HMF IRONMAN SLIP-ON CARBON
FMF powerbomb header
RENTHAL FRONT SPROCKET 13T
RENTHAL REAR SPROCKET 37T
RENTHAL R3-2 520 O-RING CHAIN, and K&N air filter with the K&N powerlid,Stage 2 hotcams camshart, and the wiseco 440 big bore kit at 12.5-1 compression ratio.
im gettin a dynojet kit that comes with 1 Main Jet CJ116
1 Main Jet CJ120
1 Main Jet CJ124
1 Main Jet CJ128
1 Main Jet CJ132
1 Main Jet CJ136
1 Main Jet CJ140
1 Main Jet Adapter DJA001
1 Fuel Needle DNO989
1 Adjusting Washer DW0001
1 E-Clip DE0001
1 Mixture Screw Tool DT008
Which of these do i need to use?? right now i have the 2004 450r needle on the 4th clip down with everything else on stock--pilot and so on, the f/a screw 2-1/2 turns out. when i give it fuul throttle it bogs out and trys to die untill i let off the gas. what is wrong and what do i need to be doing?? thanks 4 any input!1

Sorry can't help. I don't know the Dynojet numbers as they related to the Keihen. If using K jets, then I would use a 180-185 main for a starting point.

BTW, don't test jetting by idling in the driveway, see the posts above!

[trx400 rider]

ok this might sound dumb but i had this carb for about 5 mounths and never put it in. so i decided to do it and i dont under stand how to know what the pilot and main are at. for example like how you nkow its at 170 main please help i want to put this carb in thanks

[BassHunter0123]

you have to take the carb apart an look at the jets and the number will be etched into it

[zrpilot]

Originally posted by trx400 rider
ok this might sound dumb but i had this carb for about 5 mounths and never put it in. so i decided to do it and i dont under stand how to know what the pilot and main are at. for example like how you nkow its at 170 main please help i want to put this carb in thanks

The jets are in the float bowl.. refer to the picture..

Please check your PM box

[trx400 rider]

wat u mean by etched in the side

[trx400 rider]

like is there a tool or soamthing that says what the jets are set at.

[BassHunter0123]

on the side of the jet there will be a number. and that what jet size that is. they are not adjustable or set at anything if you need to adjust you need to buy another jet. hope this helps

[trx400 rider]

ok the main says 118. so if i wanted to get a 175 i can go buy it. and would it come in a set that has a bunch so i can match up the right one.and were could i get them at

[BassHunter0123]

is there like a goofy shaped star right by the number? if so they are keihin jets. that is the brand of jet and that is what comes stock. but a 118 seems incredibly small to be a keihin. there is a conversion chart on one of these threads on here to compare different brand jets. i recommend going to www.jetsrus.com and buy them. you can buy a jet kit which is a assortment of different sizes or buy them individually. a 175 keihin jet makes sense but that 118 cant be a keihin

[smokindw]

when installing the 450r carb if i just move the clip on the stock needle and put a 180-190k(the one that was in there stock was a 118K) main jet in it do i have 2 put a new slow jet in it(the stock one that is in there a K48) ? and also when filling the hotstart do you take out the spring or what do i have to do step by step to plug off the hotstart?? Thanks guys for ur time!!and there r 2 wires that r hanging and two holes that look like vent hole not sure what they r either-PLEASE look at the pics and help me out
http://s711.photobucket.com/albums/ww119/smokindw/

[trx400 rider]

ok im gonna go to my local honda dealer and get the kit.so what size main you think i should get and what size pilots should i get. and any other jets i need to switch.and any thing else i need.and thnks for all your guys help

[BassHunter0123]

well i am sure no expert and it all depends on yor mods. try a 175 main and keep everything the same and see what happens. its trial and error. i am going through this same process right now. one thing you need to know this is not jusy simply just bolt it on and go. you need to plug the top vent and redrill through the side. also sanding on the boots to make it fit. zrpilot has adapter for the airbox boot that makes it a bit easier and cleaner look and can always convert back. also have to block off the hot start. need 450r throttle cable. if you go back through this thread zrpilot has a good detailed description and pics on what exactly needs to be done to make this work. http://www.exriders.com/vbb/showthread.php?s=&threadid=314423

[richards]

Installed my carb today and have some questions for you guys...

First, how are you adjusting your fuel screw? I cannot seem to get to it without rotating the cab and that is a bit of a PIA when trying to fine tune. I have a bike with an FCR carb and have an aftermarket fuel screw on it that you can turn with your fingers. Anyone seen one of those for the 04-05 450R carbs we are talking about on this thread? The FCR fuel screw will not work on this 450R carb.

My other question is about tuning out a slight low rpm bog. Mine pulls pretty well from just off idle in 1st, but if I am in 2nd and let the revs get low it will bog/hesitate a bit when opening the throttle. I would like to play with the accelerator pump to see if I can tune this out. The FCR on my bike has a leak jet that you can play with as well as an adjustable AP mechanism. Any tricks to adjusting the AP on this 450R carb? Looking at it I do not see any adjustments except perhaps bending the end of the lever that actuates the AP.

For reference I am running Keihin jets, 48 pilot and 172 main, using stock 450R C55D needle with the clip in the middle groove. Engine and exhaust are stock for now.

[zrpilot]

Originally posted by richards
Installed my carb today and have some questions for you guys...

First, how are you adjusting your fuel screw? I cannot seem to get to it without rotating the cab and that is a bit of a PIA when trying to fine tune. I have a bike with an FCR carb and have an aftermarket fuel screw on it that you can turn with your fingers. Anyone seen one of those for the 04-05 450R carbs we are talking about on this thread? The FCR fuel screw will not work on this 450R carb.

My other question is about tuning out a slight low rpm bog. Mine pulls pretty well from just off idle in 1st, but if I am in 2nd and let the revs get low it will bog/hesitate a bit when opening the throttle. I would like to play with the accelerator pump to see if I can tune this out. The FCR on my bike has a leak jet that you can play with as well as an adjustable AP mechanism. Any tricks to adjusting the AP on this 450R carb? Looking at it I do not see any adjustments except perhaps bending the end of the lever that actuates the AP.

For reference I am running Keihin jets, 48 pilot and 172 main, using stock 450R C55D needle with the clip in the middle groove. Engine and exhaust are stock for now.

Before you change the AP, I would try this,

1)Bump up to a 50 pilot and re-adjust the idle mixture screw

2)Try moving the needle down one notch to the 4th

See if those changes would tune out this bog.

BTW here is the tool I use for adjusting the idle mixture. it is made by Motion Pro..

[richards]

FWIW my carb came with a Keihin 118 main in it just as trx400 rider mentioned above. How does that relatively tiny main work on the 450R? Wondering why it is set up that much differently for that engine which is similar in displacement to ours.

[zrpilot]

Originally posted by richards
FWIW my carb came with a Keihin 118 main in it just as trx400 rider mentioned above. How does that relatively tiny main work on the 450R? Wondering why it is set up that much differently for that engine which is similar in displacement to ours.

Completely different engine that has different vacuum characteristics.

[richards]

Thanks for the reply, I'll play with the needle and a larger pilot as suggested.

And that is a sweet looking tool but almost $90 from Motion Pro, yikes! I'll have to think about that, not sure it is worth it to me

[zrpilot]

Originally posted by richards
Thanks for the reply, I'll play with the needle and a larger pilot as suggested.

And that is a sweet looking tool but almost $90 from Motion Pro, yikes! I'll have to think about that, not sure it is worth it to me

Agreed, a lot of money. Bought mine off Ebay. Paid like $60

I can also change main jets with it as well!!!

So for me it was worth the money.

[trx400 rider]

so would i have to get any other thing at honda besdies the main and pilot

[zrpilot]

Originally posted by trx400 rider
so would i have to get any other thing at honda besdies the main and pilot

The only other things I can think of are a fuel line and a throttle cable, both from a 450R

[trx400 rider]

i have a fuel line all ready from a 450 but it leaks gas out by were the line connects to the gas tank.the hose hole is to big.and i called honda and i askes to get from 150 all the way to a 175 main does that sound good and wat size should i get in pilot.

[trx400 rider]

i live in florida so the climate i geuss is something involde with the size jets u get.it is .50 in the bore.it has a k&N air fillter and a procircut pipe. so you have an idea of what jets to get

[zrpilot]

your right the 450R fuel line is a little big, but a new one should work with an aircraft style hose clamp.

I would center the mains around the 175, so get a 165, 170, 175, 180, 185

Get a 50 and a 52 pilot

[trx400 rider]

ok and the hot start can i jut cut that off.and what is that bout were u have to drill a hole.is that the same thing as drilling out the vent and cap the hole wit a screw.or are those different

[zrpilot]

Originally posted by trx400 rider
ok and the hot start can i jut cut that off.and what is that bout were u have to drill a hole.is that the same thing as drilling out the vent and cap the hole wit a screw.or are those different

I do believe you are referring to the vent needing to be drilled out. See my thread about the 450R carb install

[riderssb250x]

I have a 440ex hotcam stage 1 or 2 I forget, lrd pro-4 exhaust, no airbox just a k&n filter, and a 450r carb

what shoukd ny jeting be to start causse I think I was runing lean and that's why I blew a headgasket im not sure what's in there now,

what pilot?
what main?
air fuel screw turns out?
needle clip position?

I ned to know this asap even if its a lil on the richer side itd be better then lean..

[zrpilot]

Main: 185
Pilot: 52
Stock needle on the 4th from the top

that is only a start. You need to go through the work of getting it just right.


Originally posted by riderssb250x
I have a 440ex hotcam stage 1 or 2 I forget, lrd pro-4 exhaust, no airbox just a k&n filter, and a 450r carb

what shoukd ny jeting be to start causse I think I was runing lean and that's why I blew a headgasket im not sure what's in there now,

what pilot?
what main?
air fuel screw turns out?
needle clip position?

I ned to know this asap even if its a lil on the richer side itd be better then lean..

[tom416ex]

okay here we go. Still trying to get the jetting right on my 400 with the 450 carb. I have a 50 pilot which i sued for all these tries. Started out with a 172 main,needle in the middle and 2 turns, all over the place, puffin black smoke, Way to much fuel. Went to a 168, kept needle the same, still runnin like crap, still smoking, with bout 2-3 turns. Same deal. Threw a 165 main in, started getting better, but was bogging like crazy. Finally went to a 160, it idels and purrs like a kitten, no more black smoke at all. Actually sounds better than before, the screw it out a ton. I get on it and it bogs, then picks up like crazy, then bogs again. What do you guys think i should do. Im thinking a 165 back in there and mess with the screw until its right, it just seems like it wants to go, but it dont. This is killing me!

[richards]

Originally posted by tom416ex
okay here we go. Still trying to get the jetting right on my 400 with the 450 carb. I have a 50 pilot which i sued for all these tries. Started out with a 172 main,needle in the middle and 2 turns, all over the place, puffin black smoke, Way to much fuel. Went to a 168, kept needle the same, still runnin like crap, still smoking, with bout 2-3 turns. Same deal. Threw a 165 main in, started getting better, but was bogging like crazy. Finally went to a 160, it idels and purrs like a kitten, no more black smoke at all. Actually sounds better than before, the screw it out a ton. I get on it and it bogs, then picks up like crazy, then bogs again. What do you guys think i should do. Im thinking a 165 back in there and mess with the screw until its right, it just seems like it wants to go, but it dont. This is killing me!

What brand of jets are you using? A Keihin 172 main runs pretty well for me and my engine is stock except for this carb and an ignition advance key. Almost sounds like you are using dynojet jets, a dynojet 160 would be in the right ballpark, equivalent to a Keihin 178 or so. Could also be a Mikuni 160 which is equivalent to a Keihin 190 or so.

And the "screw it our a ton" could be a problem. You do not really want to go out more than 3-4 turns on your fuel screw, at that point it is pretty wide open. If you need it out that far it is time for a larger pilot. If you screwed it out more than 4 turns then it could be unseated from the threads and messing with the mixture somehow.

[tom416ex]

Originally posted by richards
What brand of jets are you using? A Keihin 172 main runs pretty well for me and my engine is stock except for this carb and an ignition advance key. Almost sounds like you are using dynojet jets, a dynojet 160 would be in the right ballpark, equivalent to a Keihin 178 or so. Could also be a Mikuni 160 which is equivalent to a Keihin 190 or so.

they are keihin jets. I have a 416 kit and a stage 1 cam. I tried for 2 days with teh 172. it was getting soooo much fuel, it started coming out of the bottom of the carb bowl. Ever since i changed it to a lower main, that problem stopped. Im getting frustrated. hahaha

[tom416ex]

so im thinking of trying the 165 or the 168 again and maybe about 2-4 turns (ballpark) with the screw and see what happens,but it just seems like it doesnt enjoy that. I take the carb off when the bigger mains are in it and the intake boot was pretty wet with gas along with the tube connecting to the cylinder. (that was worse) and it was smoking when i took it off.

[richards]

Originally posted by tom416ex
it was getting soooo much fuel, it started coming out of the bottom of the carb bowl.

Tell us more about that, maybe there is some other issue with your carb like a sticking float or float needle? Maybe someone else here has other ideas. But sounds like something is wrong and you are getting extra fuel leaking from somewhere.

Oh and are you sure the enricher circuit (what most folks call the choke) is off? That could do it. Make sure that pin is pushed all the way down. When it is pulled up it lets more fuel into the carb to help start a cold engine.

[zrpilot]

Originally posted by richards
Tell us more about that, maybe there is some other issue with your carb like a sticking float or float needle? Maybe someone else here has other ideas. But sounds like something is wrong and you are getting extra fuel leaking from somewhere.

Oh and are you sure the enricher circuit (what most folks call the choke) is off? That could do it. Make sure that pin is pushed all the way down. When it is pulled up it lets more fuel into the carb to help start a cold engine.

Also check float level!!

[trx400 rider]

can you leave the choke on?

[tom416ex]

Originally posted by trx400 rider
can you leave the choke on?

it doesnt help. Ive come to the conclusion that i may need a bigger pilot. I messed with it more today, it is responding a tad better, i can get it to max out, its only when it is at a low rpm is when it bogs, once i hit the gas shes gone, no problem at all, just at putting around. I am going to throw a 52 pilot in there at some point and see what she does. Im almost there. Its got the 160 main, with the 50 pilot, screw is about 2 turns out. Any advice once again would be awesome! Thanks guys.....

[zrpilot]

Originally posted by tom416ex
it doesnt help. Ive come to the conclusion that i may need a bigger pilot. I messed with it more today, it is responding a tad better, i can get it to max out, its only when it is at a low rpm is when it bogs, once i hit the gas shes gone, no problem at all, just at putting around. I am going to throw a 52 pilot in there at some point and see what she does. Im almost there. Its got the 160 main, with the 50 pilot, screw is about 2 turns out. Any advice once again would be awesome! Thanks guys.....
Where is the needle at?

zrpilot

[tom416ex]

Originally posted by zrpilot
Where is the needle at?

zrpilot

it is in the middle, it was almost at the top when we started jetting this thing, so i moved it to the middle. Also, i forgot to mention, i tried all the other mains today, went from having the screw all the way in to almost out, and couldnt get her to turn over, the 160 seems to be the only one that would.......

[zrpilot]

Originally posted by tom416ex
it is in the middle, it was almost at the top when we started jetting this thing, so i moved it to the middle. Also, i forgot to mention, i tried all the other mains today, went from having the screw all the way in to almost out, and couldnt get her to turn over, the 160 seems to be the only one that would.......
Move the needle DOWN one notch

Oops, should have been more clear, move the CLIP down one notch.

[smokindw]

i finally got my 450r carb on and it was well worth the hassle!! Thanks to ZRPILOT's adapter and advice it wasn't really that bad!! And i also wanted to thank sanddragging25 also!! I have a 200 main, 50 pilot, needle on the 4th notch down and the a/f screw 2 1/2 turns out. But my only prob is the throttle cable!! When i pull on the cable by the thumb throttle it moves and revs up and when i push the cable back towards the thumb throttle housing it revs back 2 normal!! I dont know if i got a broke cable or whats going on?? It seems to get stuck out when riding cuz it is revving itself when riding!! i have tried to move the idle screw and also tried moving the adjustment into different places but it still wont work!! HELP PLEASE

[tom416ex]

Originally posted by zrpilot
Move the needle DOWN one notch


that will give it less fuel correct? Im not too sure how the needle works....... do you think i should even bother with the 52 pilot or what?

[zrpilot]

Originally posted by tom416ex
that will give it less fuel correct? Im not too sure how the needle works....... do you think i should even bother with the 52 pilot or what?

No, if you move the CLIP down one notch, it effectively raises the needle, giving it MORE fuel


On the pilot, if you are more then 3 turns out on the idle mixture screw, then yes go to a bigger pilot

zrpilot

[tom416ex]

Originally posted by zrpilot
No, if you move the CLIP down one notch, it effectively raises the needle, giving it MORE fuel


On the pilot, if you are more then 3 turns out on the idle mixture screw, then yes go to a bigger pilot

zrpilot
okay i understand. and i beleive i am about 3 turns, maybe a hair more out on the screw. looks like ill bump it up to a 52 and see what happens. Do you think this will help the bogging in my low rpm? Like i said before, thats the only place its struggiling, everywhere else is gooooooood

[zrpilot]

Originally posted by tom416ex
okay i understand. and i beleive i am about 3 turns, maybe a hair more out on the screw. looks like ill bump it up to a 52 and see what happens. Do you think this will help the bogging in my low rpm? Like i said before, thats the only place its struggiling, everywhere else is gooooooood

Yes I think it will help. And I would still experiment with that needle, afterall it does not cost anything to do that !

[tom416ex]

Originally posted by zrpilot
Yes I think it will help. And I would still experiment with that needle, afterall it does not cost anything to do that !
yes, this is true! thanks for all the help zr. I owe you

[richards]

Let's have a discussion about how to tune main jets... Used to be you could read spark plugs but that was iffy back in the day and it is worse now as newer gasoline additives can affect plug color. Very few of us have access to dynos with sniffing equipment to determine air/fuel ratios at different RPMs and loads.

Anyone have some relatively easy ways to test jetting? Something the average person can do with normal tools an a little time? I'm thinking main jets and needle position here - pilots can be done by feel and by ear, and the standard needle taper seems to work OK. But selecting the proper main jet and needle position is not straightforward.

If you are way too small or too large on the main you will get lean or rich symptoms that are pretty easy to recognize. But as mentioned earlier in this thread, fine tuning the main size can make a significant difference. I believe one guy posted dyno results showing a couple of HP difference between two adjacent main sizes.

Anyone have ideas on how to recognize differences at this level without a dyno? I'm thinking a rolling start timed run in one gear from x mph to y mph would be easiest. If you use WOT you will be isolating the effect of the main jet size. Would want to do on the same road/trail, preferably with same temperature, humidity, wind, etc. Would need a speedo of some sort, GPS would do ok but is not smooth and will introduce some errors. Could use a simple stopwatch in your left hand for the time since you will be in a single gear for the test and do not need to use the clutch.

Needle height setting is a little more tricky as it will have different effects at different throttle settings. Maybe the best answer here is to find the right main as described above, or some other method, then move the needle up and down to get the best "seat of the pants" throttle response. Other ideas?

[richards]

Originally posted by zrpilot
Agreed, a lot of money. Bought mine off Ebay. Paid like $60

I can also change main jets with it as well!!!

So for me it was worth the money.

Wanted to thank you for the idea, had not considered that it could be used to change main jets as well. And thinking about it I'm sure there will be other uses. Motion Pro had some refurbished ones on sale so I ordered one.

When you change mains with this, do you do that through the cap on the bottom of the float bowl or do you have to remove the bowl? Looks like it could be done through the cap and that would make it a lot easier.

[zrpilot]

Originally posted by richards
Wanted to thank you for the idea, had not considered that it could be used to change main jets as well. And thinking about it I'm sure there will be other uses. Motion Pro had some refurbished ones on sale so I ordered one.

When you change mains with this, do you do that through the cap on the bottom of the float bowl or do you have to remove the bowl? Looks like it could be done through the cap and that would make it a lot easier.

Through the cap.

Also I am working on a jetting thread in response to your post above. I would welcome your comments once it is done.

zrpilot

[zrpilot]

Originally posted by richards
Let's have a discussion about how to tune main jets... Used to be you could read spark plugs but that was iffy back in the day and it is worse now as newer gasoline additives can affect plug color. Very few of us have access to dynos with sniffing equipment to determine air/fuel ratios at different RPMs and loads.

Anyone have some relatively easy ways to test jetting? Something the average person can do with normal tools an a little time? I'm thinking main jets and needle position here - pilots can be done by feel and by ear, and the standard needle taper seems to work OK. But selecting the proper main jet and needle position is not straightforward.

If you are way too small or too large on the main you will get lean or rich symptoms that are pretty easy to recognize. But as mentioned earlier in this thread, fine tuning the main size can make a significant difference. I believe one guy posted dyno results showing a couple of HP difference between two adjacent main sizes.

Anyone have ideas on how to recognize differences at this level without a dyno? I'm thinking a rolling start timed run in one gear from x mph to y mph would be easiest. If you use WOT you will be isolating the effect of the main jet size. Would want to do on the same road/trail, preferably with same temperature, humidity, wind, etc. Would need a speedo of some sort, GPS would do ok but is not smooth and will introduce some errors. Could use a simple stopwatch in your left hand for the time since you will be in a single gear for the test and do not need to use the clutch.

Needle height setting is a little more tricky as it will have different effects at different throttle settings. Maybe the best answer here is to find the right main as described above, or some other method, then move the needle up and down to get the best "seat of the pants" throttle response. Other ideas?

Here it is:

Jetting help thread (http://www.exriders.com/vbb/showthread.php?s=&threadid=394028)

[tom416ex]

Originally posted by zrpilot
No, if you move the CLIP down one notch, it effectively raises the needle, giving it MORE fuel


On the pilot, if you are more then 3 turns out on the idle mixture screw, then yes go to a bigger pilot

zrpilot

hey man
i dropped the needle, tried all the other mains with the 50 pilot. same deal, sputtering like crazy on take off. took my buddies 55 pilot and tried the same deal with all the mains, turned the screw from all the way in to just about out on all of them! still the same problem. i dont know anymore. i give up.... you have any ideas?

[richards]

Originally posted by tom416ex
hey man
i dropped the needle, tried all the other mains with the 50 pilot. same deal, sputtering like crazy on take off. took my buddies 55 pilot and tried the same deal with all the mains, turned the screw from all the way in to just about out on all of them! still the same problem. i dont know anymore. i give up.... you have any ideas?

Have you checked the choke circuit? If it were leaking it would be dumping in extra fuel and that could explain your symptoms.

[zrpilot]

Originally posted by tom416ex
hey man
i dropped the needle, tried all the other mains with the 50 pilot. same deal, sputtering like crazy on take off. took my buddies 55 pilot and tried the same deal with all the mains, turned the screw from all the way in to just about out on all of them! still the same problem. i dont know anymore. i give up.... you have any ideas?

All those changes and the quad is STILL running the same?

IF so then there is something else going on.. I would take the carb off and check everything:
1) clean it
2)adjust the float
3)check to see of the needle valve is shutting the flow of gas off
4)Hot start is COMPLETELY plugged
5)You have the right jets in it, including the needle
6) Make sure there are NO air leaks
7)Verify the AP is working
8) Like Richards said, check the enrichment circuit
9) verify the air cut-off valve is working correctly
10)ETC....

Otherwise I do not know?

Did you buy this carb used? If so, maybe sell it for what you paid and buy a new one!

zrpilot

[tom416ex]

Originally posted by zrpilot
All those changes and the quad is STILL running the same?

IF so then there is something else going on.. I would take the carb off and check everything:
1) clean it
2)adjust the float
3)check to see of the needle valve is shutting the flow of gas off
4)Hot start is COMPLETELY plugged
5)You have the right jets in it, including the needle
6) Make sure there are NO air leaks
7)Verify the AP is working
8) Like Richards said, check the enrichment circuit
9) verify the air cut-off valve is working correctly
10)ETC....

Otherwise I do not know?

Did you buy this carb used? If so, maybe sell it for what you paid and buy a new one!

zrpilot
The choke is totally off. well, its still there, i just dont use it. i took the yellow clip off. I just dont get it. im bringing it to a buddy i know that has a shop. hes gonna figure it out for me. He saids it gotta be something so stupid that im just missing......

[richards]

Originally posted by tom416ex
The choke is totally off. well, its still there, i just dont use it. i took the yellow clip off.

But are you sure the choke is in the off position? Whether the yellow lever is there or not the choke can still be locked in the on position. If the pin us pulled up all the way it is on, if the pin is pushed down all the way it is off.

[tom416ex]

Originally posted by richards
But are you sure the choke is in the off position? Whether the yellow lever is there or not the choke can still be locked in the on position. If the pin us pulled up all the way it is on, if the pin is pushed down all the way it is off.

its totally down.

[tom416ex]

i think i may know what the problem is! ill have to look tomorrow, dont have the quad with me, at my rents torn apart. anyways. i think when we cut that breather vent off the top of the carb and drilled through the side one, when filling the top hole, i may have put tooo much rvt sealent on the top along with the rivit i put it. Im beginning to think that the vent is blocked not allowing proper aif flow, thats why its bogging like a son of b***h! is this possible?

[zrpilot]

Originally posted by tom416ex
i think i may know what the problem is! ill have to look tomorrow, dont have the quad with me, at my rents torn apart. anyways. i think when we cut that breather vent off the top of the carb and drilled through the side one, when filling the top hole, i may have put tooo much rvt sealent on the top along with the rivit i put it. Im beginning to think that the vent is blocked not allowing proper aif flow, thats why its bogging like a son of b***h! is this possible? It CERTAINLY could be the problem. Let us know what you find

[tom416ex]

Originally posted by zrpilot
It CERTAINLY could be the problem. Let us know what you find
i def will man. ill be sooo mad if thats all what it was. but at the same time, happy! This could be the cause for this most likley... Correct?

[zrpilot]

Originally posted by tom416ex
i def will man. ill be sooo mad if thats all what it was. but at the same time, happy! This could be the cause for this most likley... Correct? It could be, but I just don't know... sorry

[tom416ex]

Originally posted by zrpilot
It could be, but I just don't know... sorry
if its not, then im blowing it up. haha

[zrpilot]

Originally posted by tom416ex
if its not, then im blowing it up. haha

I got a better idea... send it to me and I will get it running like a champ. I won't even charge ya for my services....

I'd send it back to you... eventually :devil:

[tom416ex]

Originally posted by zrpilot
I got a better idea... send it to me and I will get it running like a champ. I won't even charge ya for my services....

I'd send it back to you... eventually :devil:

haha, yeah man. maybe another time!

[tom416ex]

okay, heres the deal. i brought it to that kid that i know. he cant get it running for crap. he took it all apart, and it still wont work, its running richer than rich. so come to find out, one of the vent holes for the tube is alll clogged as hell, and hes gonna have to rip the entire carb apart and blow all the holes out and get it right. but for now hes gonna give me another 450 carb that he has, and is going to keep my other one and just fix it. so problem solved........ for now... until i brake something else....

[piglet400ex]

zrpilot do you have any more of those adapters?

[zrpilot]

Originally posted by piglet400ex
zrpilot do you have any more of those adapters?

PM Sent

[matt14c]

I have the carb im using the ZR adapter. I will be putting it on a FRESH 416 is this safe or recomended? Im getting the JE 10.8:1 416 or 415 whatever. Have full exhaust, KN, Big Gun Rev, HC stage 2, right now i have no lid but i think i maybe going to put a outerwear lid on. All needed holes are plugged with RTV I tested them a little with my air compressor with the blow gun and they seal. Im thinking 175, 50, 2 1/2 out. Im just worried about tuning in a carb for a motor thats will have a fresh piston in it.

[zrpilot]

Originally posted by matt14c
I have the carb im using the ZR adapter. I will be putting it on a FRESH 416 is this safe or recomended? Im getting the JE 10.8:1 416 or 415 whatever. Have full exhaust, KN, Big Gun Rev, HC stage 2, right now i have no lid but i think i maybe going to put a outerwear lid on. All needed holes are plugged with RTV I tested them a little with my air compressor with the blow gun and they seal. Im thinking 175, 50, 2 1/2 out. Im just worried about tuning in a carb for a motor thats will have a fresh piston in it.

It is wise to be worried, but consider this...

When breaking in a new piston you will probably see brief periods of full throttle, where during those periods the motor will be mostly on the main jet circuit operation, correct? However, adjusting the needle might be a better option, doing so will affect most of the area that the new motor will be running in (1/4-3/4 throttle). I would run on the 4th or 5th notch down from the top which might be just right, if not a little rich.

The main and pilot sound like a good place to start once you are jetting for final..

zrpilot

[riderssb250x]

need help i need my jeting setup,
450r carb
440 kit
ported and polished
lrd pro4 full exhaust with ceramic coated headers
no airbox

i have in it now a 186 k main, 52 pilot, middle position on clip and i beleive 2.5-3 turns out on the screw

it pops on decel and if its at idle and i hoit the throttle it stalls

[riderssb250x]

need help i need my jeting setup,
450r carb
440 kit
ported and polished
lrd pro4 full exhaust with ceramic coated headers
no airbox

i have in it now a 186 k main, 52 pilot, middle position on clip and i beleive 2.5-3 turns out on the screw

it pops on decel and if its at idle and i hoit the throttle it stalls

[zrpilot]

Originally posted by riderssb250x
need help i need my jeting setup,
450r carb
440 kit
ported and polished
lrd pro4 full exhaust with ceramic coated headers
no airbox

i have in it now a 186 k main, 52 pilot, middle position on clip and i beleive 2.5-3 turns out on the screw

it pops on decel and if its at idle and i hoit the throttle it stalls

Snapping the throttle open in neutral is not a good way to determine if it has a stumble. My 400EX that WAS JETTED correct on the dyno would do that.

Jump up to a 54 pilot, re-adjust the pilot screw and drop the clip down one notch.

Report back.

[riderssb250x]

alright im trying that today should I leave in the 185 main or would the 190 probably be a better choice since I have one laying around?

[zrpilot]

Originally posted by riderssb250x
alright im trying that today should I leave in the 185 main or would the 190 probably be a better choice since I have one laying around?
Leave the 185 in

[riderssb250x]

alright zr today i messed around with it for a while and i got it pretty good its just running a bit rich like when you crack the throttle u can see a real disztinct black smoke puff not always but some times, it responds good and the upper rpms are great it halls, idle is good and all im just concenered about the black smoke ? should i just leave it and be safe runing ia lil fat then leanen it out and casuing damage in the long run?

also on decel it pops a lil not as bad as it was before but it does a lil bit i know 4 strokes do sometomes so its probably normal.

as of now im at this..
Main- 180
Pilot- 55
Needle- Middle position


should i just leave it since its pretty good or can i eliminate that poping on decel? i dont wana mess it up though cause it does run good and responde good that is on the street it hasent been on the dirt or sand yet..?

[zrpilot]

Originally posted by riderssb250x
alright zr today i messed around with it for a while and i got it pretty good its just running a bit rich like when you crack the throttle u can see a real disztinct black smoke puff not always but some times, it responds good and the upper rpms are great it halls, idle is good and all im just concenered about the black smoke ? should i just leave it and be safe runing ia lil fat then leanen it out and casuing damage in the long run?

also on decel it pops a lil not as bad as it was before but it does a lil bit i know 4 strokes do sometomes so its probably normal.

as of now im at this..
Main- 180
Pilot- 55
Needle- Middle position


should i just leave it since its pretty good or can i eliminate that poping on decel? i dont wana mess it up though cause it does run good and responde good that is on the street it hasent been on the dirt or sand yet..?

Did you adjust the pilot screw? How many turns out are you?

[riderssb250x]

i csant remember off the top of my head but id say around 2? i noticed now it shoots out flames if you rev it real high and let off? and stillbackfires some when decelerating and its a bit hard starting when cold?

itrs geting really frustrating i beleive that i shold be good with the 55 pilot that alread on the big side, what do you siujest?

how many turns out should i be on the screw?

also about the flames? i know that means im way to lean help me out

[riderssb250x]

zr im not runing an airbox by the way.., just a k&n and outerware.. maybe hop up to the 190 main?
it pulls good at the top of the gear and decent all through jkjust backfirues a bit on decel..


also when idling sometimes when i rev it up it shoots a few flames?

HELPPP

[zrpilot]

Originally posted by riderssb250x
zr im not runing an airbox by the way.., just a k&n and outerware.. maybe hop up to the 190 main?
it pulls good at the top of the gear and decent all through jkjust backfirues a bit on decel..


also when idling sometimes when i rev it up it shoots a few flames?

HELPPP

You have to make 100% sure your hot start is properly plugged

PLEASE READ THIS ALL THE WAY THROUGH!!!

My 450R carb install (http://www.exriders.com/vbb/showthread.php?s=&threadid=314423)

[Wheelie]

FWIW--I ran a 48 pilot with my 440 when I was running gasoline. A 440 should in no way be lean on the idle circuit with a 55 pilot installed.

250x--a 48 or 50 pilot and 185-190 main should work well with your setup. Clip on the needle on the 4th notch from the top.

[flyboy1294]

Hoping someone can help me out...
My carb is still not here yet, but I went ahead and tore into my stock carb to try to see what size range of jet I'd need to buy...

At the moment I'm doing 185/40 on the stock carb. I run 110 octane, a full exhaust, 440 kit, K&n filter with open airbox.

If someone could give me an idea of what to try on the 450 carb it'd be appreciated :)

[blankenship]

hey everyone well it is sad to say but i have recently traded my 440ex for a crf450 it was a great deal and i am happy but i have heard of this mod for the AP for my carb and am not sure about it i the mod does anyone know about this i will post the link to the step by step artical if oyu guys could let meknow hat you think that would be great


http://www.squadpage.com/pandora/Pr...%20AP%20Mod.pdf

[richards]

Probably a better topic for another board specific to the bike, but since you asked... That is a somewhat common mod for the AP on an FCR carb, did similar on my KTM. By messing with the adjustment screw (the gap), using saftey wire or an o-ring, and adjusting your leak jet size you can adjust when the AP starts, how long it pumps, and the volume of fuel it pumps. You do all of this to eliminate any bog and get the strongest response when whacking the throttle open.

Results will be dependent on any other mods you have so that guy's settings may not be exactly what you need, you may need a different gap, different leak jet, etc. Google "adjustable leak jet" and you will see there are some places that sell a mechanism that eliminates the leak jet and lets you adjust the AP volume using a screw. I have and R&D power pump and it works well - is much easier to tune since you do not have to keep pulling the bowl off to try different leak jets.

[blankenship]

thank you i know its not exactly thread specific but i know that some people are using the fcr carb on there 400ex and i was wondering if any of you guys have heard of this AP mod and if it would be worth me doin it myself and possibly to inform anyone who did not already know about this

[richards]

Hopefully anyone using the FCR will speak up here... Most of us here are talking about the carb that came on the 450R in 2005-05 which is a round slide Keihin, not the FCR.

If you have any stumbling when you open the throttle quickly on your CRF then messing around with the AP and leak jet will be worthwhile, if you keep at it long enough you should be able to eliminate the stumbling. A lot of bikes that use the FCR benefit from this tuning, I recommend looking around on thumpertalk as there are likely lots of CRF owners over there that have been through this exercise.

[childert79]

I NEED HELP! I bought a 05 400ex with a blown engine and no carb. I just built it into a 416 with wisecon 11:1, Hotcams stage 2 cam, K&N filter kit w/o lid, hot rods crank, and it had an amr stage 3 rev box and monster coil. Since It didn't have a carb on it I got me a 450r mikuni 40mm carb but I don't even know where to start jetting since it didn't originally come with a carb. Please help me I can give you watever information i can.

[childert79]

I NEED HELP! I bought a 05 400ex with a blown engine and no carb. I just built it into a 416 with wisecon 11:1, Hotcams stage 2 cam, K&N filter kit w/o lid, hot rods crank, and it had an amr stage 3 rev box and monster coil. Since It didn't have a carb on it I got me a 450r mikuni 40mm carb but I don't even know where to start jetting since it didn't originally come with a carb. Please help me I can give you watever information i can.

[zrpilot]

Originally posted by childert79
I NEED HELP! I bought a 05 400ex with a blown engine and no carb. I just built it into a 416 with wisecon 11:1, Hotcams stage 2 cam, K&N filter kit w/o lid, hot rods crank, and it had an amr stage 3 rev box and monster coil. Since It didn't have a carb on it I got me a 450r mikuni 40mm carb but I don't even know where to start jetting since it didn't originally come with a carb. Please help me I can give you watever information i can. Is this carb a round slide or flat slide?

[BassHunter0123]

looking for an opinion for my jetting. i currently run a 450r carb with k&n no airbox lid. for the most part it runs good but i think its a little rich. when i punch the throttle from nothing to full throttle it wants to die. and yes it is under a load and not in neutral. i put my lid back on the other day and spits and sputters and runs like crap. should i go down on the main a size or 2? i think its getting too much gas. and no i havnt checked my plug yet, im going to next time im out riding.currently running a 185 main

[zrpilot]

Originally posted by BassHunter0123
looking for an opinion for my jetting. i currently run a 450r carb with k&n no airbox lid. for the most part it runs good but i think its a little rich. when i punch the throttle from nothing to full throttle it wants to die. and yes it is under a load and not in neutral. i put my lid back on the other day and spits and sputters and runs like crap. should i go down on the main a size or 2? i think its getting too much gas. and no i havnt checked my plug yet, im going to next time im out riding.currently running a 185 main What pilot are you running? Where is the needle set to?

[BassHunter0123]

50 and 4th notch

[zrpilot]

Originally posted by BassHunter0123
50 and 4th notch How many turns out on the idle mixture screw?

[BassHunter0123]

3

[zrpilot]

Originally posted by BassHunter0123
3 If it TRULY three turns out, then this is where I would start.

Main: 170 or 175
Pilot: 52, then re-adjust your mixture screw

[BassHunter0123]

its for sure 3 turns out. for the most part it runs fine and i rarely go from idle to punching it. but i want the jetting as good as i can get it

[zrpilot]

Originally posted by BassHunter0123
its for sure 3 turns out. for the most part it runs fine and i rarely go from idle to punching it. but i want the jetting as good as i can get it UP the pilot and re adjust the fuel mixture screw

[BCs406ex]

well here is another noob question..... I have a 416 high comp. wiesco, k&n, open air box, r4 pipe, and hot cams stg 2

my buddy has a bone stock 2002 450r carb, what do i need for a main and a pilot?



And if its not to much to ask does anyone have a how-to for the 2002 carb? I have only seen ones for a 04 05

Srry just surfed through here and will continue but i got a race on saturday and would like to see if i cant bring out some pony's

[childert79]

Originally posted by zrpilot
Is this carb a round slide or flat slide?

Flat

[zrpilot]

Originally posted by childert79
Flat Sorry. I have no experience with that carb.

[iownatoyota]

just got my 450r carb on and am running a 58 piolet with a 205 main jet , needle is on the 3rd clip from the top. she needs fine tuning still though.

[Wheelie]

Originally posted by iownatoyota
just got my 450r carb on and am running a 58 piolet with a 205 main jet , needle is on the 3rd clip from the top. she needs fine tuning still though.

What are your mods?

[childert79]

That sucks. I can get another carb if i have to so what would you recomend?

[zrpilot]

Originally posted by childert79
That sucks. I can get another carb if i have to so what would you recomend?

IMO the 2004-2005 450R carb is a better choice. There are many posts and other that have done this mod. IF you search for posts by my name you will find a post called "My 450R Carb Installation" Also I make an adatper that makes this carb VERY easy to intall. Ask around and I think you will find other that think my adapter makes the install a snap!


zrpilot

[Wheelie]

Originally posted by zrpilot
IMO the 2004-2005 450R carb is a better choice. There are many posts and other that have done this mod. IF you search for posts by my name you will find a post called "My 450R Carb Installation" Also I make an adatper that makes this carb VERY easy to intall. Ask around and I think you will find other that think my adapter makes the install a snap!


zrpilot

I concurr. ZR's adapter is a work of art and a must have part for anyone installing this carb on an EX.

[childert79]

How much is the adapter and do ya know anyone who sales the 04-05 carbs here on the forums?

[zrpilot]

Originally posted by childert79
How much is the adapter and do ya know anyone who sales the 04-05 carbs here on the forums?
The adpater is $45 plus $3 for shipping. You can try to find one here on the classifieds or for something like $175 get a BRNAD NEW one from www.servicehonda

[iownatoyota]

Originally posted by Wheelie
What are your mods?

duncan double barrel exhaust, twin air filter on an open air box, 450r carb,

[childert79]

Sweet! I'll pm you when I find a carb.

[zrpilot]

Originally posted by iownatoyota
duncan double barrel exhaust, twin air filter on an open air box, 450r carb,

I'm sure Wheelie will add his opinion... wait I HOPE HE GIVES HIS OPINION !!

I think you are a little off. Here is what I would try:

First: if you are less then 1 turn out on the fuel mixture screw then drop the pilot. If the fuel mixture screw is 1.5 (but no greater then) 3 turns out, leave it alone.

Second: Put the needle on the 4th notch down

After that I'll bet your quad will still run pretty good, but may have a little sluggishness at 3/4 or more throttle. IF so drop the main jet down and see if the 3/4+ throttle gets better or worse and go from there until it runs good all around

[iownatoyota]

k ill give her a go, thanks

[v0lcom13sn0w]

zr pilot, you seem to know a lot about adding the 450r carb to the 400ex... so i got a question for you... first off i came up on a 05 450 carb i want to put it on... i have 400ex with a fmf powercore 4 slip on. K and N filter. no airbox. sparks advance timing key. i live in oregon and ride the dunes a lot so its 0-250ft elevation. what pilot and main jet do you recommend starting out with... needle position... AF screw mix... any input would be very much appreciated thanks bro.

[matt14c]

Well my plug color is almost perfect looking. A little on the rich side but im happy with that. Im running 185 main, 52 pilot, 4th posisiton from top, and about 2 1/4 turns out. Its a bit hard to start. I have to pump the throttle a few times then turn over then it doesnt want to settle down and idle regular until it has a few minutes on it. The main thing im worried about is im having some pretty bad backfiring popping through the exhaust at deceleration. I just moved from the 50 p to the 52. Before that with the 50 I couldnt get it to idle good at all, but the popping was far less severe. Hot start and other hole is plugged. Not leaking. All tubes/hoses are not leaking and tight using hose clamps/expansion clamps. Suggestions?

[matt14c]

With having the day off today I finally finished up the dialing of my carb. Im running a 416 JE 10.8:1, air box lid with an outerwear sheet and couple 1" holes in the box, Full Big Gun Evo R exhaust, stage two hot cam, KN filter and of course 04-05 450 carb. With it tuned in the best I think I can do its been about 61-64 degrees today since I have been working on it.

I had good plug color just a little on the rich side and good idle just alot of deceleration popping through the exhaust and took a few pumps of the throttle to get her started when cold and I was running 185 main, 52 pilot, 2 1/2 turns out and 4th slot down on the needle. I hated the popping and knew it wasnt right so I wanted to dial it in right. I started by going up on the pilot to a 55 and 2 turns out on the a/f screw with the same main 185 and same needle posistion 4th from top. Popping virtually gone none at all idle was pretty high and was adjusted as far as i could with the ilde adjustment knob. Was easier to start it fired on the second turn or so of the motor which was a great imporvement over before. Only problem was that it got a bit richer.

So my final setup that im at now is 180 main, 55 pilot, 1-1/2 turns out a/f screw, 4th notch from top on needle. Starts up much better, plug color is where I want it, and Finally no popping on deceleration! I honestly cant believe I need that large of a pilot especially looking at some other similar setups and where people have there setting but I guess you cant argue with results! :D

[ZJTurbo]

440ex, 11:1, stage 2 hotcam, sparks 6 degree advance. hmf slip on, no airboxlid, uni filter, 450r carb with 110 octane. I am at sea level what are you jet pro's guessing. Thanks for any info in advance,

-Ben

[bkelley]

450r carb, White Brothers E-Series exhaust, stock header with welds ground, ESR Airbox Eliminator Kit. Riding elevations are usually under 5,000' but occasionally we get close to 10,000' on some trails.

What jetting should I run?

[childert79]

I need some help with jetting my 450 Carb.
11/1 416 w/xr400 headgasket and eliminated base gasket
Mild port and Polish head
Stage 2 hotcam
Insane performance airbox w/k&n filter and Outerwear lid
Fmf powerbomb header and Lrd slipon
Amr stage 3 revbox
And the 450 carb
Elevation is 860ft above sea level

What should I start at?

[zrpilot]

93 octane!

main 170-180
Needle: 4th from top
Pilot: 50-52
A/f Screw, adjust as needed

[childert79]

Sorry. Was in a rush. Yup. I'll be running 93. Thanks for the quick reply zr!

[Cbeasley]

If you are over a keihin 165 for the main jet on a 450r carb then you have an air leak. 165 is the stock main jet for the 450 so with it on a 400 you shouldnt be higher than that. I have a 165 on the 440 in my sig and a 50 pilot and it runs great!

[zrpilot]

Originally posted by Cbeasley
If you are over a keihin 165 for the main jet on a 450r carb then you have an air leak. 165 is the stock main jet for the 450 so with it on a 400 you shouldnt be higher than that. I have a 165 on the 440 in my sig and a 50 pilot and it runs great! Please don't compare jetting requirements of the 450R with the 400EX using the same carb. They are different motors and (without going into a lot of theory) WILL use different mains. It is possible the 400EX may need a LARGER main.

Zrpilot

[Wheelie]

Originally posted by Cbeasley
If you are over a keihin 165 for the main jet on a 450r carb then you have an air leak. 165 is the stock main jet for the 450 so with it on a 400 you shouldnt be higher than that.

This statement is incorrect. Most modified 400's require a larger jet than a 165. On gas I ran a 200 main and 48 pilot and didn't have any air leaks.

There is a dyno chart of a 426 with a 450r carb and he was running a 185 and had a A/F chart to prove that the jet was spot on.

Heck, I'm running a 245 main now--granted I run a high content of ethanol.

[Cbeasley]

Just saying i thought my 440 was running great with a 210. Found out i had an air leak with the hotstart because that holes runs all the way through... i filled it with silicone and put a 165 in it and its running 100% better and pulls so hard.

[zrpilot]

Originally posted by Cbeasley
If you are over a keihin 165 for the main jet on a 450r carb then you have an air leak. 165 is the stock main jet for the 450 so with it on a 400 you shouldnt be higher than that. I have a 165 on the 440 in my sig and a 50 pilot and it runs great!

Not to beat a dead horse, but my friend TriRon5 did a comparsion of a stock 400EX carb to a 450R carb on his internally stock 400EX motor and ended up at a 162 main on the dyno. The stock motor on a 168 main made .7 of a horse LESS then the 162. I doubt most riders would feel the difference between the 168 and 162 and be PERFECTLY happy running the 168 which is 3 mains HIGHER then the main of 165....

Again please don't compare one motor's jetting to another (450 vs 400). Too many variables, such as dynamic compression, cam timing, vacuum signal, exhaust configuration, ETC... This list of variables is quite long.


ZR

[Wheelie]

The stock 450R main jet is a 118.

[pontiacgtp97]

Okay, I bought a 450R carb and adapter a couple months ago and I'm just now getting around to putting it on. I'm running a 426, 11:1 piston, stock head, Pro-Circuit slip on, Stage 1 Hotcam. What settings should I start with?

[sheweezy]

Yeah, as wheelie said 04-05 main jet stock is a 118, fcr stock is 165

[PLF]

Hey guys,

just installed 450r 04-05 carb in my 400ex yesterday and got some time to adjust it today, here is my setup

Bone stock motor (original) except for:

- K&N filter w/outerwear
- Outerwaer Lid (big open rectangle)
- Sparks 6deg Advance
- Grinded Exhaust welds
- 2008 450r Muffler w/spark arrester


Here is what I did so far:

- 52 pilot
- Needle 3rd clip from top
- 165 main
- about 3 1/2 turns out

I had severe decel popping until I went past 3 turns out and at 3 1/2 they are mostly gone and idle is perfect but I did not try further

- If I rev it standing still it will pop as revs go down

- I felt like I lost bottom end, throttle response is instanious and WOT seems good but low revs seems to be a bit weeker but hard to tell only going straight in the courtyard lol

What you guys recomend/think ??

THanks

[zrpilot]

Originally posted by PLF
Hey guys,

just installed 450r 04-05 carb in my 400ex yesterday and got some time to adjust it today, here is my setup

Bone stock motor (original) except for:

- K&N filter w/outerwear
- Outerwaer Lid (big open rectangle)
- Sparks 6deg Advance
- Grinded Exhaust welds
- 2008 450r Muffler w/spark arrester


Here is what I did so far:

- 52 pilot
- Needle 3rd clip from top
- 165 main
- about 3 1/2 turns out

I had severe decel popping until I went past 3 turns out and at 3 1/2 they are mostly gone and idle is perfect but I did not try further

- If I rev it standing still it will pop as revs go down

- I felt like I lost bottom end, throttle response is instanious and WOT seems good but low revs seems to be a bit weeker but hard to tell only going straight in the courtyard lol

What you guys recomend/think ??

THanks

Move the clip down one notch and try that. What is the temps?

[PLF]

Originally posted by zrpilot
Move the clip down one notch and try that. What is the temps?

3 C

37 F

[zrpilot]

Add 3-5 points to the main.

[PLF]

Originally posted by zrpilot
Add 3-5 points to the main.

+ raise needle ?

or only change main to 168-170 ?


And from about what temp should I lower main ?

And BTW guys, 06+ muffler on 400 sounds freakin loud !! even with insert...

[zrpilot]

Originally posted by PLF
+ raise needle ?

or only change main to 168-170 ?

Do both, first drop the clip which actually raises the needle first then try the main. As the temps get to about 50-60 F then go back to a 165.

[PLF]

At my surprise the needle was already on the 4th clip. So I put it on the 3rd (normal stock position) and started over.

I was having a real hard time setting the idle and removing the intale tube there were lot of gaz in it, so I put a 50 pilot instead of the 52 and followed the procedure by listening to the engine (no tach) and managed to get it pretty much dead on with the idle and no more standing still reving pop. (3 tuns out)

I put the 168 in and I still get a bit of popping on decel mainly in first gear and almost none in second (can't try quad around here)

Response is fantastic, power seems linear and wot pulls great, no hesitation at any rpm (but remember these are not real riding conditions only backyard 50 feet runs...)

I looked for intake leaks and have none, still need to check for exhaust leaks but what else could affect that decel pop ?

[CJM]

Lean pilot. Could try 3 turns out the air/fuel screw or a larger pilot jet.

For my 400ex carb no matter what I get some popping if I engine brake. I went from a stock 38 pilot to a 42 and turned the air/fuel screw out 3 turns-still pops slightly so I gave up.