fouled the first plug

5 replies to this topic
  • sirthumpalot

Posted July 28, 2001 - 02:59 AM


Well, I fouled the first plug in my '01 426, but I think that this one was my fault. I was in a rush to clean the carb so I only turned it sideways, removed the bowl and sprayed some cleaner up through the jets. When I tried to restart it, there was almost no compression and definitely no fire. None.. After 3 kicks with the choke (normal routine) I figured it was flooded. About 100 kicks later with the hot start it sputtered for about 5 seconds and that was the end. Put in a new plug and it started first kick with the hot start pulled (stone cold engine) and ran great. Seemed richer than before (needed no choke at all while cold) so maybe the carb was dirtier than I thought. Today's the test, I'm on my last plug so prey for me. :)

Oh, I almost forgot, the moral of the story is don't let carb cleaner get into the motor!

[This message has been edited by sirthumpalot (edited 07-28-2001).]

  • MikeOK

Posted July 28, 2001 - 03:46 AM


it's a cool bike anit it sir...

  • Boit

Posted July 28, 2001 - 03:58 AM


It's an odd thing about these engines when suddenly there is no compression. I can't imagine that carb cleaner could cause this even if you sprayed it directly into the intake runner. My '00 sat up for about 2 months while I recuperated from a rib injury and the engine had little compression when I tried to start it. After about 25 kicks, it suddenly started and regained it's normal compression. Why? I dunno. Two things come to mind. Perhaps the rings needed a little more oil on the cylinder wall to seal better(not too confident about this one), or, a valve(s) didn't seat properly once I kicked the engine through. This one makes more sense to me because the valve stem guides could have become dry after such a long time of no use causing a valve to hang up momentarily....or become lethargic in it's stroke. After about 25 kicks or so, the engine suddenly started(and this was after a lazy kick). I let it run for about 3 minutes and shut it down to check the compression. I'm 185 pounds and could stand on the kickstart lever and it would hold my weight for about 3 seconds. That's as good as new. I would really like to know what was the cause of this. My KLX did the exact same thing once, so it must be related.

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  • yzernie

Posted July 28, 2001 - 07:25 AM


Remember to not leave the choke on for more than about 10 seconds. That will eat a plug in about...well...10 seconds!!!

If you can start it on a cool day without the choke, you need a leaner pilot jet.


  • sirthumpalot

Posted July 29, 2001 - 02:19 PM


I couldn't imagine the carb cleaner causing the no compression either, but I have done nothing else to the bike and it had full compression just before I cleaned the carb. Very odd...

In any event, the temperature was in the low to mid 90s and the humidity was in the high 90s when it started cold with the hot start pulled. The next day with similar temps it felt pretty rich for the first 1/4 throttle on all stock jetting. In the afternoon when it cooled off a bit the bike started running a lot better. Unfortunately I couldn't reach the fuel screw with the screw driver which I brought with me to the track that day. :)

  • yzernie

Posted July 29, 2001 - 03:41 PM


As the weather cools, the air will get more dense making it run a little leaner. That may be why it ran beter as the weather cooled. I had to go one leaner on my pilot and drop the needle by one clip position.

Be careful with the fuel screw by making 1/4 turn adjustments at a time. Adjust both leaner and richer and keep adjusting until you find where it runs the best.


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