I'm tired of this Quad! Need help....

[Sportrax 400EX]

OK here is the deal.... I have a 2002 400EX, it has a K&N filter with Outerwear, Full Big Gun Quiet series exhaust and mildly vented airbox lid. I have tried everything to get this thing to perform right. I have gone from 155 main jet with 40 pilot to 170 main and 42 pilot and everything in between. The thing just lacks power no matter what. My brother has a bone stock 02 400ex and can pull hard on me everytime. Were talking like 4 quad lengths here. I can barely get the front wheels off the ground on it also. Please help me out, what am I doing wrong here??? Currently the setting are as follows. 155 main jet, 42 pilot, needle in 3 and air screw 2.5 turns out. Does the Big gun quiet series exhaust just suck? Should I just go back to stock on everything to get my power back? After spending all this money on mods I would think I would see some kind of gains....not a LOSS in power. thanks for the help!

D.

[crowdedhead]

try a 146 main jet...your mods are close to mine and thats what i'm running... 146 main jet with mixture screw 3.5 turns out.

hope that helps...

[Doibugu2]

Keep us posted with the outcome. I'd like to see what you find works the best. How quiet is the big gun? I heard one without the quiet core, and it was loud as ****!

[Sportrax 400EX]

It's not to loud at all. Very nice sound to it. I'll try the 146 main. should I keep the pilot and needle where they are?

D.

[spincr4hire]

Did you try adjusting the thumb throttle cable?
Mine came from the dealer with about 25% of play, it does make a difference. What is your altitude? I'm in Kentucky, and I run a 165 main with factory pilot, w/needle half way between (3 down), I run a Yoshi slip-on, though. Also I have a hole about the size of a football in my airbox lid, along with a K&N and Outerwear. It sure was a big difference from stock when I did these mods.

[Sportrax 400EX]

throttle cable is adjusted, that was one of the first things I checked. I'll have to try to jetting you mentioned and see how it runs with that. My altitude? not sure. I'm in the washington DC area if that helps.

Thanks
D.

[spincr4hire]

Call Terry @ Marcum's or Jeff@The Quadshop, they should be able to tell you exactly what you need.

[Sportrax 400EX]

I'll give them a try also.....thanks!
Thanks for the feedback guys...keep em coming!!


D.

[YZROOSTINYA]

have you taken the baffle out of your stock air filter?

pull the bafflr and cover the hole with some duck tape. i know this is a rig but just try it. this is what i did.
stock bike no airbox holes. took out baffle and went to a 150 main(148 stock) gave me more top end and oulled longer harder at full throttle.

i now have a complete pro-meg e-series exhaust, k&n with outerware and 4 uni vents in my lid and a 155main. no pilot or screw changes,and no needle chages. also i went down to 8 discs since the exhaust came with 12.

you should NOT be using more than a 160 main. and even that is way fat in my opinion. i hear guys on hear talking about 170 mains with slip ons. you people must be crazy. its is a stock motor. the only thing a exhaust will do is provide less back pressure. the reason i went up on the mainis the k and n. my plug is beutiful and my quad rips.

maybe your air is twice as dense as mine, or maybe my brain is twice as dense?


i live in pa(sea level) and also ride in the mountains 1-2k above. no probs in either area.

i would pull the baffle and see what happens.

also i have pulled my airbox lid and the ONLY thing it did was make noise. i couldn't feel dink. maybe you guys now sumpin i dont. you have not put in a cam(more air/out lift/duration) high comp pistion, head work or anything. your jettting should be very close to stock.

give this a whirl and let us know.

Well it will cost a little money, but I think you have a jetting problem, so take it to a shop with an EGT gauge and have them jet the bike for you. They can dial it in so it will run right. The Big Gun exhaust hurts the top end over stock but add tremendous torque so you will need to gear up to take advantage of what the pipe gives you. You should smoke him when everything is tuned in right.

[Sportrax 400EX]

I have tried blocking the vents on the lid, tried a new lid with no holes, tried no lid and all the same results. I was hoping to avoid the expensive shop route. If all else fails I'll have to do that I guess.

D.

[Zingnut]

Hey YZROOSTINYA,

What do you mean by Baffle.

Is the baffle the inner metal core of the stock filter or the metal inside of the metal screens.

I am feeling stupid but am not understanding what you meant.

[Sportrax 400EX]

I figured he meant the metal core piece. I'm using a K&N filter with the core part on it already.

D.

[Big - D Racing]

Don't use the core part on the k&n, use only the K&n with outerwear nothing else. Remove your lid. I'd use a 150 main. Contact big gun on their recomenned jetting. Run what they say also, your exhaust, i'd be willing to put money on it puts out less horse power than your stock. The big gun race series hp gains are little over stock, the quiet series is that much less. The quiter the exhaust, the less power it will produce. My recommendation take the exhaust off and sell, than get a loud *** exhaust or if your looking for quite get the stock back on. All quiet exhaust's on the market put out nearly the same or even less power than the stock one, the difference is they look nicer. Call Duncan Racing they'll talk to you over the phone and they know everything about jetting on the 400ex carb. Tell them what you run and they'll tell you what size jet, mixture screw position, and everything. Duncan Racing 619-258-6306 They're open until 5:00pm pacific time Tuesday thru Friday

[Sportrax 400EX]

VERY GOOD INFO!! Thanks much everyone. I really appreciate the tips and info. I'll try calling them also.

MUCH thanks

D.

have u tired a 158, i would

[YZROOSTINYA]

i was talking about the entire metal core on the stock filter, not just the mesh wire glued in. i didnt know you had a k and n so it doesnt matter.

[crowdedhead]

so sportrax 400ex, did you try the 146 main?

just checking in with you to see if you have things figured out.

also, are you running a stock lid? or have you put holes in it?

[Sportrax 400EX]

I put the pilot back to stock last night, put in the 146 main, DynoJet needle set on clip 3 and set the screw to 2 3/4 turns out. I'll take it out tomorrow and see how it runs. I have to take it to my brothers house to try it since the cops in my area will ticket me if I test it on the streets etc. in my area. Gotta love living in a stuck up county. Right now I have the stock air box lid with 6 UNI air box vents in it. Running a K&N filter with OW. And the Big Gun Exhaust.

We'll see how it does. If it is still off I'm just ging to say F it and take it to a shop. :(


Thanks
D.

[two_baaalls]

Where you live SportTrax?
I'm in Front Royal.

Got some experience with these things, but I'd rather see your bike and check it out for myself rather then just throw suggestions at ya.

Adjusted the valves lately? You have been doin plug checks right?

Going to Hatfield?

[crowdedhead]

it should be close to running right with the 146, if anything you may need to up the main jet one more size since your running a modified air box lid.

but try what you have now first.

let us know how it runs when you can test it.

[YZROOSTINYA]

148 is stock, why would you go to a 146? especially with a k and n?????

[Taco]

Originally posted by YZROOSTINYA
148 is stock, why would you go to a 146? especially with a k and n?????

They are talking about the dynojet 146. Keihln and Dynojets #s do not correlate with each other.

[Sportrax 400EX]

I live in Alexandria, VA. I mostly ride in Stafford though at my brothers house. I just did a valve adjustment last night when I had everything apart. Plug looked good also. I can't make the Hatfield trip this time unfortuantely. I hope to make it out next time though. When I get the quad running right i'd like to come out to 4PunksDad's place and ride some.

One thing i just thought of.......should I set the air screw back to stock (2 1/4 out) or set it at 3 turns out (I'm below 3000ft) like the DynoJet instructions say??


I just got an emial back from Big gun here is what he said to do, sounds like a bit much on the pilot to me:

48 pilot jet
155 -158 main jet
Drop clip on needle one position from stock
Air screw set to 3 turns out.


Thanks
D.

[RideRed04]

I think big gun is refering to keinin (sp?!?!) jets, not dynojets.

[Sportrax 400EX]

does anyone know what the conversion is between the K&N and Dynojet jets are? I have been using a combo of both. I thought they were the same sizes just designed a little different.

Right now I'm at 146 main with Dynojet jet. Does the advice you guys have given apply or do I need to get the K&N 146?

Thanks
D.

[Ensign]

Originally posted by Sportrax 400EX
does anyone know what the conversion is between the K&N and Dynojet jets are? I have been using a combo of both. I thought they were the same sizes just designed a little different.

Right now I'm at 146 main with Dynojet jet. Does the advice you guys have given apply or do I need to get the K&N 146?

Thanks
D.

I believe the K&N jets are actually Dynojet jets, unless you meant to say Keihn instead of K&N? Anyone you call will need to know which type of jets you're dealing with.

The Dynojet and Keihn jets are not the same size. Last year, on the 2001 400ex I had, I think I ran a 165 Keihn main with a vented airbox lid and White Bros. E-series slip-on. It ran great. I live in Baltimore and rode at similar elevations as D.C. Not that you're probably riding IN D.C. though, right? ;)

Can the quiet core be removed from that pipe? If you don't like the pipe, let me know because I might be interested in buying it.

[Sportrax 400EX]

The ones I have are DynoJet. You have to add their adapter and the small jet. The one I took out was one piece and was longer.

D.

[crowdedhead]

do like the dynojet instructions say and set it 3 out.

check also on the jet stage your going for. the instructions should be split into two parts...stage 1 and stage 2. depending on which one you go with, turn out the mixture screw as instructed.

[Steven]

I know how you feel. I have 2 400ex's.

Both bikes have a K&N stage 2 jet kit and filter. One bike has an FMF Mega MaxII slip on and the other has a WB R4 pro-meg complete exhaust system.

The bike with the FMF slip on and stock header pulls harder at the top of the powerband and the bike with the WB header and R4 pulls harder on the bottom end. I have played with jets on them forever and I always get the same results.

Both bikes with run 66-70 mph depending on the day and cleanliness of the filter, but the one with the stock header pipe and FMF always pulls harder on top.

I run a dynojet 165 main on the FMF slip on and a 170 dynojet main on the R4 Pro-meg at sea level. A dynojet 160 main was to lean becasue in each bike it caused it to loose acceleration. Its nice having 2 bikes to compare when doing jetting changes. It really helps when trying to determine an improvment in acceleration.

Hope this helps some. My jetting was done at sea level.

Steve

[Sportrax 400EX]

Steven, thanks for the info. I had to work late last night so I'll be testing things out tonight. I'll post on Monday and let you all know how I did.

THANKS!!

D.

[Sportrax 400EX]

I took it out last night and it seems to pull harder in the top end but I'm still running slower in the low end. I'm going to pull the plug out tonight and see if it still looks to be running to rich. Will keep you posted.

D.

Are the K&N jets numbered to Keihin or Dynojet ??

I had recently switched from a 160 K&N (was a little too lean) to a 168 Keihin (now a little too rich) so I would like to know if they are on the same size or numbering system.

I had helped a friend jet a piped raptor and we went nuts switching between the OEM and dyno jets.

Why dont they all just follow the same specs etc.

[Sportrax 400EX]

Phill at Dynojet said they design the jets for K&N so the numbering is the same with those two. I'm not sure on the other.

D.

So anyone have any idea what the diff was between the KN 160 and Keihin 168 is??

[zephead400ex]

YZROOSTINYA sending you a pm.

[Sportrax 400EX]

Wooo Hooo..I finally got it right. Here is what it turned out to be.

Main Jet-#146 (Dynojet)
Pilot Jet-#38 (StockHonda Jet)
Air Screw-3 1/4 turns out.

The bike now pulls hard and has no problem keeping the front wheels up through third gear. I check the mixture 3 times with new plugs each time and did the rolling stop test and it had perfect color. I'm so glad this nightmare is finally over.
One major thing I learned with this. Call the experts at Dynojet or ask someone on the board here who has jetting experience if your having problems. I talked to Big Gun, K&N and many shops and all of them were way off on the jetting specs. They had me running very rich with their settings. Again, thanks to everyone who replied for the advice and help!

D.

[yellow_ho_01]

you said it could now keep the front end up in 3rd... not to disapoint you, but you should be able to pull the front end up and wheelie in 5th with only using alittle body weight...(well, i do have a 14T front sprocket, so that helps...) bring your quad out this weekend.

[Sportrax 400EX]

I haven't gotten that good yet at riding to do a good wheelie. I'm still learing how to control it. I tried it a few times and wiped out. :)

I don't think I'm doing to bad for only having the bike a few months. I still need a lot more practice to do the fun stuff though.

D.

[NTPRacing#19]

dude i dont think with just a slip on silencer and airfilter with lid mods is gonna have to require any jetting change. I got a buddy who bought a fmf powercore silencer and it had a stock airfilter on it and it was very doggy. i told him to just add an airfilter to it and it will even out the powerband. Once he got the air filter and it ran very strong after it was evened out. 170 main seems too damn big unless its right for your elevation. If you havent figured out whats wrong with it set all the jettings and pilots and ***** back to the stock settings and go from there.

i think the only time you have to play around with jetting is when you have a full exhaust with an oversize header. just small stuff like silencers and filters dont need a new jetting size.

If im wrong someone tell me otherwise. Its just what i have learned

[NTPRacing#19]

oh you fixed it i didnt read the last page, Yeah sounds like stock settings to me.