400ex pilot jet

[xtullyx16]

So my friend gave me a 48 pilot jet but its way shorter than my 45 pilot jet.. does it matter?? it threads into my carb but its way down in the pilot area while all the rest stick out or are flush with the pilot hole..

[drew416ex]

I dont know how much it would affect anything, but why do you need a pilot jet that big?

[xtullyx16]

idk 45 will start then it starts cutting out.. 50 runs fine it just i need to choke it some times after I turn it off because it floods the carb with gas

[xtullyx16]

i got a 426ex also

[XSR03Preddy]

If it's flooded, the choke is the last thing you should be using. If it's flooded, you need to hold the throttle wide open.

[xtullyx16]

Originally posted by XSR03Preddy
If it's flooded, the choke is the last thing you should be using. If it's flooded, you need to hold the throttle wide open. \

wouldnt that put more gas in the carb?? idk all ik is the 45 pilot makes mine sputter while idling and the 50 ran fine cept it just seemed slightly sluggish.. soo i think a 48 would be good.. idk why i need a such a big jet..

[XSR03Preddy]

When you use the choke, it creates more vacume in the carb.. Which pulls more fuel. If you hold the throttle wide open, it allows more air into the motor, which pumps the wasted(flooded) fuel out of the motor. I just tuned a buddy's 440ex, and it runs great with just a 42p.

[xtullyx16]

hmm idk man.. the 45 ran like crap.. the 50 ran better..

[xtullyx16]

myabe its cause i live in Ohio.. also what main is ur buddy running?

[GPracer2500]

Maybe your fuel screw isn't set right.

[XSR03Preddy]

We have a 175k in it right now.

[xtullyx16]

Originally posted by GPracer2500
Maybe your fuel screw isn't set right.

alright gpracer im stmped... ok.. when i first built my 426ex i started it up and ran it with my stock setting with a pipe and filter.. that jets were 155 main.. 42 pilot.. stock clip... it ran like ****.. it would start up but the topend was terrible...soo i put in 175 main and 50 pilot.. it started fine seemed slightly sluggsh but it felt like it ran 100x better lol.. no i just put a 45 in.. it was cutting out but if i gave it more throttle like 1/2 or held it open it ran fine.. soo i put a 48p in it and it wont even start.. well it did for a second but i had to keep reving it.. i checked my plug hoping to see if it would tell me what my pilot was doing.. the plug was black.. so its rich.. wtf! im soo confused.. i'd put my 50p in there if i could .. also my pilot/air screw is turned 2.5 out i have never messed with it.. it has been like that wtih the 50p 45p and 48p in and out.. i have a 42 i guess il go try it but ti doesnt make sense it started excellent with a 50.. its just that when the other day i was riding it in my yard and in my woods slightly hard.. it had a hard time starting and idling... then i took the 50p out and put in my 45p and it ran like crap... :ermm:

[XSR03Preddy]

You have not mention'd messing with the needle. I would try a 42p, needle on the middle(3rd clip), and 175 main. Run that, and see how it does. If uptop is fine, the main is right. Set the idle, and go from there. If you have off idle problems, try to adjust the mixture screw.

[xtullyx16]

okay.. im not trying that hahha not yet.. the main problem now is idling/starting.. i got it started with the 42 but its doing the same as the 45p.. at 1/8th throttle punch it seems to cutout/skip.. it shoots flames out.. way lean!!!??? also could my timing have jumped?? and how do i tell?

[XSR03Preddy]

You need to see where the clip is on the needle. That way we can see which way you need to go.

[xtullyx16]

pred guy, the needle has not affect on how my quad starts and idle's btw my needle is in stock position.. and how do check my timing?

[XSR03Preddy]

Originally posted by xtullyx16
okay.. im not trying that hahha not yet.. the main problem now is idling/starting.. i got it started with the 42 but its doing the same as the 45p.. at 1/8th throttle punch it seems to cutout/skip.. it shoots flames out.. way lean!!!??? also could my timing have jumped?? and how do i tell?

You are stating in this post that you are having problems from 1/8th throttle, the needle can change this area.

[xtullyx16]

my bike wont even idle.. idk i think im taking it sumwhere.. maybe a dyno but it wotn even idle......ahhh !!:mad:

[GPracer2500]

Originally posted by xtullyx16
alright gpracer im stmped... ok.. when i first built my 426ex i started it up and ran it with my stock setting with a pipe and filter.. that jets were 155 main.. 42 pilot.. stock clip... it ran like ****.. it would start up but the topend was terrible...soo i put in 175 main and 50 pilot.. it started fine seemed slightly sluggsh but it felt like it ran 100x better lol.. no i just put a 45 in.. it was cutting out but if i gave it more throttle like 1/2 or held it open it ran fine.. soo i put a 48p in it and it wont even start.. well it did for a second but i had to keep reving it.. i checked my plug hoping to see if it would tell me what my pilot was doing.. the plug was black.. so its rich.. wtf! im soo confused.. i'd put my 50p in there if i could .. also my pilot/air screw is turned 2.5 out i have never messed with it.. it has been like that wtih the 50p 45p and 48p in and out.. i have a 42 i guess il go try it but ti doesnt make sense it started excellent with a 50.. its just that when the other day i was riding it in my yard and in my woods slightly hard.. it had a hard time starting and idling... then i took the 50p out and put in my 45p and it ran like crap... :ermm:

There's a golden rule in carb jetting: Only change one thing at a time. If you start changing two things at once it's too hard to keep track of what's what.

If the original problem was at larger throttle openings (you said "top end was terrible" but remember to focus on throttle openings, not necessarily rpm) there was no reason to change the pilot jet.

Go back to the 42 you started with and put in a new plug (or at least clean off any deposits from the old plug). Then tune each circuit (pilot, needle, main) separately.

[xtullyx16]

Originally posted by GPracer2500
There's a golden rule in carb jetting: Only change one thing at a time. If you start changing two things at once it's too hard to keep track of what's what.

If the original problem was at larger throttle openings (you said "top end was terrible" but remember to focus on throttle openings, not necessarily rpm) there was no reason to change the pilot jet.

Go back to the 42 you started with and put in a new plug (or at least clean off any deposits from the old plug). Then tune each circuit (pilot, needle, main) separately.

i did change the main from 175 to 165.. 165 was too lean.. i was waiting on getting a bigger main since my local dealer was closed today.. so i had other pilots laying around so i wanted to switch them since i thought my 50 pilot was to big.. like i said before i changed my 50p to a 45p it wont idle and at 1/8th throttle it cuts in and out .. so tonight i put in a 42 cause everyone is telling me my pilots to big.. soo yeah i try that 42p and my bike barely want sto idle like usual and after reving it in neutral to get it to idle it backfires and shoots a flame out the exhaust and quits running haha.. so its way to lean or the timings off .. so idk im confused as heck and ready to give up cause my bike wont even idle..im ready to pay big bucks to have sumone fix this bike so i can ride it!:mad:

[xtullyx16]

gp i think ill pay ur flight ticket and gas to come to my house and get my bike running like a top! haha

[xtullyx16]

i put my 50p back in.. the one that it ran on before.. and it still wont idle and backfires.. how could my timing jump?? and if my timing did jump what happens to my timing chain?? could it have stretched or sumthin?

[xtullyx16]

NVM all why it was sputting was casue there was no gapping in my spark plug ... so i just fixed with a flat head screw driver.. idk if it was from threaded in to tight or maybe my base gasket when i built my motor was to thin, like it was the wrong base gasket,and my piston smacked it.. but i think its just from me threading it in too much.. i feel dumb:ermm: