can you find the problem?

I have recently purchased a 99 yzf400 that is in fair condition. The idle seems to hang going into berms, and in neutral if i blip the throttle a popping noise occurs during the de-acceration of the motor. I have cleaned the carb numerous times. The accelerator pump had plenty of dirt in it, but is clean now. My jetting is 180 main(stock175) Pilot-stock and the clip is moved to the fifth position. Elevation is sea-level. The mixture screw is one and a half out. Everything else is stock. Today i tried to see if the timing was right but the spark plug wire clip for the timing light wasn't picking up the signal. I have checked the TPS and is OK. No air leaks and the cables are fine. Any information would be appreciated greatly

Thanks Greg NJ

I have a 00'426 and when I leave off the throttle I get that popping and crackling going on, and the bike does not want to start very easy either. I have yet to find out why? sorry I can't help you, still trying to figure it out myself. Let you know if I have any luck. LATER DAYS!!! Hit-man

302 and Hit-man, The popping and crackling you're experiencing is most likely caused by a lean condition in your idle/slow circuit. Try turning the fuel screw out in 1/4 turn incriments until the situation improves or just goes away. Do not turn it out any further or it'll be too rich. This is a fairly simple solution to try. If it doesn't help, just keep track of the number of adjustments so you can put it back where it was. Hope this helps.

You're both experiencing a lean condition. I ran into this while trying to solve a plug-fouling condition that turned out to be the cdi. A lean pilot will lead to a 'run-on' sympton when blipping the throttle slightly from idle. On early YZFs the trick was to turn the pilot screw out to 2+ turns or go 1 richer.

THANX, dirtdad and blbainb, next time riding I will try that and see how I make out. Would this also make it hard to start? Thanx again guys!!! LATER DAYS!!! Hit-man



like a kid again!

00 YZ426F

01 TT-R125L (my son's)

91 CR125

83 YZ490

74 Hodaka Super Combat

i turned the pilot jet out two and a quarter turns out and that did the trick. It cleared any other problems that i had complaints of. It's a miracle. Thanks a lot guys.

Glad to hear this was so simple. It's still surprising that tipping the bike to the side would be enough to speed it up. Have fun 302!

Well I tried to start my bike today and I kicked it 20 times nothing. Pull the plug out put another one in, old but good its all I had. Kicked it 20 more times, would get a little sputter, than I would blip the throtle and get another sputter, blip the throtle a couple more times, a better sputter, then after that several times I would get it to run 4 or 5 sec. and it would shut off, did that 3 times :D Then my foot hurt to bad and I was very :) and before I did something I would regret, I quit. Any Idea's would be great!!! Hit-man


00' yz426f LATER DAYS!!!

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