Question about Yamaha YZ 250 Motorcycles

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94 Yz 250 Runs Strong and Fast after it warms up a little, smoky and boggy when it first starts. Had Motor checked by Mechanic, he said has slight loss of compression but other than that strong engine. My issue is that after it has been ridden for 20- 30 minutes and I stop in gear(With Clutch in) It makes a Pinging sound until it gets back to Idle. If I put it N it seems to stop right away. It almost seems like the engine is dieseling, but I am concerned it may be in the bottom end i.e the crank bearing. The Bike does seem to blow more oil than most,I think last guy ran at 40 to 1 I have repacked pipe and changed fuel but it seems to be pushing allot of oil out of the pipe, it runs down the pipe and onto swing arm... not sure if this a symptom or not.

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Probably could use a valve job

Posted on Jan 30, 2010


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Hello I have an 98 yz 250 it will not start when cold I can give it a shot of gas in the air box and it fires rite up and will restart as long as its warm and runs great but will not once its cooled down...

Sounds like you have a carburator issue.
The choke richens (Adds more fuel) to allow a cold start. Have the carb checked by someone with an idea of what to look for. Make sure all passages are clean and clear.
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Mar 30, 2010 | 2003 Yamaha YZ 250

1 Answer

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1 Answer

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1 Answer

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