Another jetting ?

[ltz400/400ex]

I have a 03 Z400, I have read all of the posts and I do not see anywhere where somebody is running the same setup as I am. I ordered a yoshi comp serieds pipe and a K&N jet kit. I plan on running it with the airbox lid on. I was wondering what i should do jetting wise.

[zeus54]

with the lid on and the snorkle on use 122 or 124, without the snorkle use a 144 or 146, without the lid use 160 or 162 and finally for better performance use an EHS airbox lid and snorkle removed with a 168, note you got to keep the the slosh cup on the main jet it's a piece of plastic that surrounds the main jet

[edltz]

correct me if im wrong but a stock 03 ltz 400 has a stock jet of 130,i have one and mine just has a little more compression and i put a 134 in mine and it runs great

[YFZ450Ridr]

Originally posted by edltz
correct me if im wrong but a stock 03 ltz 400 has a stock jet of 130,i have one and mine just has a little more compression and i put a 134 in mine and it runs great

correct. my dads 04 z400 was completly stock and i put a uni filter, outerwears, and took the airbox lid off. then i rejetted to a 175 main jet and left the pilot and needle stock and WOW it runs so much better. tons more throttle response and bottom end. worth it and it was all only like 60 bucks from magic racing. best mod you can ever do for the money.

[kc 300EX]

I strongly reccommend buying a good jet kit. My FMF jet kit came with every size I'll ever need, plus the new needle.

The only thing it doesn't come with is a new pilot jet. Im not sure where you're at or what the temps are like there, but for me the bigger pilot really helps in the winter and with better starting.

[zeus54]

Originally posted by edltz
correct me if im wrong but a stock 03 ltz 400 has a stock jet of 130,i have one and mine just has a little more compression and i put a 134 in mine and it runs great


the stock jet is larger than the the smallest dynojet kit but what you have to keep in mind is that the taper on the needle is different between the stock needle and dynojet's needle therefore your main jet may not need to be a high as if you had the stock needle..

try running the stock needle and see what kind of jet you might need i did it and had to run a 192.5:eek2:

when i got the dyno jet kit i couldn't believe that the largest jet was only a 170, so i called them and they explained to me about the difference in the needle's (this is before i had looked at the stock needle to compare).the taper helps deliver fuel more effectively