what do I need to do?

[B.C.#11TRX400EX]

Ok so i just went out and started the quad cold and after a couple of pumps it got warm and I pumped it some more and black smoke was coming out of the exhaust, do i need to change the jetting go up a size? Also in reverse it cuts in and out when i give it 3/4 throttle? Main jet too small? Pilot jet too small?help me out guys

[05DodgeDakota]

black smoke is unburnt fuel = too rich

[B.C.#11TRX400EX]

Umm does it make a difference that im on reserve on the gas tank? Haha im low low on gas

[05DodgeDakota]

what size main jet? How much fuel in the tank should not matter, unless you got bad gas or crap settled in the bottom of the tank

[Drfat400ex]

The black smoke is because you're revving it with the choke on, and reverse cuts out because it's freezing cold and the rev limiter kicks in and stauls it.

[CJM]

Its too rich anyways and he needs to ditch the dynojets.

[B.C.#11TRX400EX]

Well the choke definitely isn't on, I have 160 main (dynojets) and a 42 pilot

[CJM]

Originally posted by B.C.#11TRX400EX
Well the choke definitely isn't on, I have 160 main (dynojets) and a 42 pilot

160 is too rich still, its similar to a 180 OEM keihin.

Buy oem jets and throw that junk away. Im wouldnt tell you to do so unless they were junk..

[05DodgeDakota]

that's equal to a 177.5 oem jet. most likely too rich for just a pipe and filter

[B.C.#11TRX400EX]

No I mean I put in an equivalent to 160 the dynojet number is like 140 or somethin I think

[Stickman400]

Originally posted by CJM
160 is too rich still, its similar to a 180 OEM keihin.

Buy oem jets and throw that junk away. Im wouldnt tell you to do so unless they were junk.. When you say OEM, do you mean OEM equivalent Kehins? Or Genuine Kehins? Also OP your rev-limiter is kicking in in reverse because you have a stock CDI and they don't want you to go to fast in reverse and get hurt.

[wolfe 21]

my bike is very similar as far as mods done, except for the exhaust and it was recommended I run a 150ish keihin jet on mine. I would think maybe 2 more for the exhaust.
This could be helpful.jetting (http://www.exriders.com/vbb/showthread.php?s=&threadid=445695&highlight=jetting+chart)

James

[05DodgeDakota]

Pull the plug

[B.C.#11TRX400EX]

Alright thank guys tommorow ill get some gas and see what happens and ill check the plugs

[CJM]

Originally posted by Stickman400
When you say OEM, do you mean OEM equivalent Kehins? Or Genuine Kehins? Also OP your rev-limiter is kicking in in reverse because you have a stock CDI and they don't want you to go to fast in reverse and get hurt.

Keihin brand jets are the single best jets of course, excellent quality control. But I do have quite a few OEM equivalents I got from jets r us with no issues at all