2004 KFX400 Jetting question

[mrgixxer6]

Hey guys, first let me tell you i'm new to the quad scene and carbureted scene all together. I typically do all my work to my toys by myself, however this jetting crap has got me all screwed up..

I bought the quad used it has a DG Xcellerator Fully system on it, K&N w/Outerwears and Moose Power Kit Jet kit. it had a 138 main jet, however i was told it was way to small so i just changed it yesteray to a 150. Does this see right? It doesn't have the Snorkel Cap on it, however i still use the snorkel and keep the lid on.

Acording to the instructions with the jet kit it recomends a 144 mainjet with K&N and Hi Flow exhaust below 3000ft elevation. I know my local dealer typically ends up using 150 or larger. The Moose Power Up Kit also comes with some needle thing that has adjustable lengths. I have no friggin clue wtf that does, but it's installed.

I guess i really just want to know what i should do.. and get some suggestions from others that have a clue what is goin on.

Thanks so much
Dave

[indyZrider]

if its not cutting out or backfiring you are probably fine. the needle is just another way to adjust the rate of fuel flowing. up on the needle is leaner and down is richer. jetting a serious trial and error task. the butt dyno is going to help you alot. i would start with like a 165 and see how that does. if its too much then reduce a size and retry. the pilot jet might need to be bigger. stock is a 22.5 but almost everyone goes to a 25 or 27.5. you will need to mess with the air-fuel mix screw as well. go to z400central.com==there you will find any and everything about your bike.

[mrgixxer6]

thanks for the info man, i'm guessing the pilot jet is the other jet on the bottom of the carb? Someone else told me to try the 165 and see how that works as well. i know just going from the 138 to the 150 the bike now pulls the front wheels just shifting from 1 to 2 and a little from 2 to 3 gear. I want to really try and get max perf. from the machine without spending a whole lot more $$$.

I'm gonna put a Rev Box on it over the winter, i'm used to my GSXR that revs to 14k and i find myself hitting the 8k rev limitter alot LOL..

I'll definately check out the site you recomended and see what kind of info i can find there. again this is my first quad ever and i'm loving it!!!

[jonboy]

Welcome to the world of ATV's! :D Glad to here you're loving it.