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01 yz250f timing help

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trying to set the correct timing on yz250f. when i set it to the I on the flywheel, its not at TDC. not even close. put a little screwdriver in the spark plug hole and cranked on the flywheel and on the I mark, the screwdriver is not at its highest point. rotate 1/8 turn more and its on the highest point. flywheel is correctly on the key on the crank. cant figure this one out. any help?

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i cranked on it till the screwdriver was at its highest point (tdc according to piston) and then lined up the cams all good and kicked it but nothing. compression is great, valves in spec, cant figure out why everything is not lining up though. it ran good when i initially finished the motor. rode fine and idled, uproared a huge backfire and died. no bent valves or anything since it has great compression. also looked at the cams and the sprockets do not seem to have slipped. looks fine on the lobe angles

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Sounds like a fouled plug. Did you replace the plug yet? When you do, check for fire at the plug. If still no fire, unplug the kill switch and see if it comes back. If so, kill switch is bad. Also check for fuel in the bowl and flow.

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ill give it a shot. pretty sure the timing is way off somehow cause the I on the flywheel is not tdc. 1/8 turn later its tdc. stretched cam chain maybe?

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figured it out, the woodruff key on the crank that lines the flywheel up to the crank correctly broke. thus spinning the flywheel out of time so it wasnt sparking at the right time to fire. makes sense since the compression was fine and no valves were tapping the piston. put a new one in and we'll see how she runs tomorrow

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runs good now. real healthy. i hope some people can figure out their key is busted by searching and finding this thread. i never found any threads like it and was getting worried

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