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yz250fr problem starting/riding

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Hey,

i own a 2003 yz250fr and havent done any maintenance but oil changes,filter cleaning. i know its bad that is the only things iv done since the 8 months iv rode it:bonk: .

so i rode it hard and fast one day and it ran great, go to start it the next day to go for a little trail ride and noticed that the kicker isn't as hard to kick as it should be. being me i just started it up and took off. while i was riding it i noticed after about half throttle it rev's normal and sound like it should but the wheel spin isn't. so i rode it home and parked it. Im ready to take the motor in to the shop but i don't know what to tell them i want done.

if you can tell me what to tell them that would be great thanks.

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The first culprit to check for when your kickstarter has less force than normal is compression. Run a compression check (simple tool, easy to do)...and go from there. If it's lower than normal, the first things to check are your valves since they are probably out of spec and need to be adjusted (tightened). After that, check the piston, the rings might not be sealing correctly and need replacement.

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Hmm, can you get an accurate compression test on a bike that has an automatic compression release?

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hey, I have an 01 yz250f and had a lot of starting problems. I have a manual de-comp. release, if you have an auto de-comp. cam you cant do a compr. test, you need to do a leakdown test. you can get a good leakdown guage off of e-bay, make sure it has the right size fitting for the spark plug hole. I think it should be 10mmx1mm thread pitch. Leakage should not be more than around 10%. you could have tight valve clearance or a worn set of rings. hope this helps

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