kfx400 jetting

[Dr89]

alright guys heres what i can tell you. it doesnt idle, i have to run it with the choke half out, i think it revs like it should until half-3/4-full throttle. i know its lean but what confuses me is that it doesnt pop or backfire or anything on decel or through the gears. its like it runs right but with no power...i need some good estimates on where to start with the main jet, pilots, air/fuel screw, and needle clip.

i should prolly mention this is with a full white bros. carbon fiber exhaust and and a k&n filter with outerwear but no lid.

[Byte]

What type of jets? Mikuni, dynojet? Are you running a stock needle?

[Dr89]

yea im pretty sure the needle is stock but i was thinking about ordering a dynojet kit, would that make it any easier for me or not?

[Byte]

You probably should be running a mikuni 165 to 175 main jet. If you changed the pipe and put a K&N on there you NEED to rejet the carb.

[Dr89]

of course i need to rejet...thats why i made the thread. lol but thanks man, i just needed a starting point. do you think i'll have to mess with the pilot or needle at all?

[Dr89]

oh and what comes stock in the kfx? i dont have a manual so..

[Sandgod4]

I'd say a 165 or 170 main.. I'd bump the pilot up one also..

[indyZrider]

Originally posted by Dr89
oh and what comes stock in the kfx? i dont have a manual so..

stock main is 130 and pilot is 22.5

[Dr89]

i ordered the 165 and 170 mains yesterday but is this gonna fix my top end boggiing, like from 1/2 throttle and up, or am i gonna have to mess with the needle and the pilots?

i was also wondering if a k&n jet kit would be worth my money cause it seems like it would make the process easier, but if in the end its gonna gimme the same results as a couple $2 jets (that the dealership actually just gave me for free) then i wouldnt see the sense in buying one.

[Sandgod4]

Pilot jet is 0-1/8 throttle

Needle 1/4-2/3 or 3/4

Main 3/4 - redline

[Dr89]

ahh oh yea ok, i had my pilot and main mixed up in my head, for some reason i was thinking the pilot took over on the top end. ok so according to how i described it running im gonna have to pretty much mess with them all to get it to idle and run smooth, maybe the needle will be alright.

[kfx400isdashiz]

ok i have a slip on yosh pipe i use the stock needle settings, 23 pilot and a 190 main. it runs like a dog and when you get to thetop it my new rev litmiter really allows the motor to kick even better than i can almost stay with my buddies 660 rappy on the road i am sure if i changed gearing i could stay with him