Question about 2004 Yamaha YZ 250 F

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I just bought a 2000 YZ 250

And after running it for a bit I can not get it to open up past 3/4 throttle it just loads up and blows a bunch of smoke,I think i may be getting gear oil into my cylender how can I check this with out taking apart would the spark plug be black? Becouse its not it does have oil residue on it though.

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  • rubylea Jul 21, 2009

    So the bike has sit for 2 years and the power is unreal when accelerating until I get to 3/4 throttle if I sit in neutral and rev it a bit it sounds awesome until I try to open it up that's when she loads up and blows a bunch of smoke, if it was to say the crank shaft seal is that hard to replace? Thank you so much for your help!

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first try cleaning the jets sounds like pilot may have a blockage and its boggging down, as the bike been stood for a while ?
but also could be the crank seals

2 strokes should have a slight oil residue on them better running ruch than too lean

Posted on Jul 21, 2009

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Jan 19, 2009 | 2004 Yamaha YZ 250 F

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