Where's my compression

2 replies to this topic
  • John_H

Posted December 30, 2001 - 11:23 AM


Changed my oil, cleaned the air filter, bike started fine ran for a few seconds, started idling roughly, died and wouldn't start again. Pulled the plug and it was wet. Put it back together and wouldn't start. Tried everything choke, no choke, new gas, etc. Finally started and was running fine for about a minute, started running roughly and died. Now I have little compression (i can kick it through without the release). I've read some old posts about others with on and off compression loss. I've got a thousand miles so probably time to adjust the valves. Never been in the top end before, but wondering if I'll be able to see a sticking valve while doing the adjustment??? Just have to take turns riding the little woman's XR200 today.

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  • DOC

Posted December 30, 2001 - 11:56 AM


you are obviously running too rich, as many people seem to. this has been discussed on the 250F forum, and it is not uncommon. it has happened to me once and it scared the hell out of me. I went to the trouble of checking my valves, and they were all okay. One theory that members have is that whent he bike floods, excess fuel dilutes the oil around the piston rings and reduces their ability to seal. When you do finally manage to start the bike, the oil is quickly replenished and compression is restored. This has also been discussed on www.dirtrider.net, on their tumper forum.

  • John_H

Posted December 30, 2001 - 03:59 PM


yeah Doc, I read that on the 250 side too. If it's the rings, a small squirt of oil in the cylinder might take care of that. Sounds like you're thinking it's not a valve. Read another post where the guy sprayed some WD40 on a valve and fixed his problem. I'll tinker a bit and see what happens.

[ December 30, 2001: Message edited by: John H ]


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