can you find the problem?

8 replies to this topic
  • Guest_Guest_*

Posted March 18, 2001 - 04:26 PM


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

  • Guest_Guest_*

Posted March 18, 2001 - 05:17 PM


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

  • dirtdad

Posted March 18, 2001 - 06:18 PM


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.

  • blbainb

Posted March 18, 2001 - 07:47 PM


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.

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  • Guest_Guest_*

Posted March 20, 2001 - 04:24 PM


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

  • dirtdad

Posted March 20, 2001 - 05:00 PM



like a kid again!
00 YZ426F
01 TT-R125L (my son's)
91 CR125
83 YZ490
74 Hodaka Super Combat

  • Guest_Guest_*

Posted March 21, 2001 - 04:59 PM


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.

  • James_Dean

Posted March 21, 2001 - 07:14 PM


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!

  • Guest_Guest_*

Posted March 25, 2001 - 05:39 PM


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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