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how to check cam timing on 2010

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I'm working on a 2010 crf250 for a guy. It's starting poorly. Intakes are right on at .005. How can you tell if the cam has spun on these? Exausts are .010 and .009. I don't think those will be a problem

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Check valve lift at tdc, put a gauge on the bucket

you should have around .100"

Kim

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I'm working on a 2010 crf250 for a guy. It's starting poorly. Intakes are right on at .005. How can you tell if the cam has spun on these? Exausts are .010 and .009. I don't think those will be a problem

About the only way you can tell if the timing gear spun is if you use a degree wheel. You're valves are in spec so that's not your hard start issue. A leak down test will help determine what's going on. If a valve isn't sealing, that's going to cause a problem. I would check the obvious items like a clogged pilot jet and the carb. If the temp dropped significantly, you may need to make some adjustments on the carb or possibly re-jetting.

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like 450dk said , you can see if it spun by putting it at TDC on OVERLAP and if both intake and exhaust valves are open the same amount ( around 2 to 3 mm ) it is good

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make sure the cam is not 180 degrees off.. cam lobes should be facing back. i dont know if its the same on a 2010 but thats how it is on my 06

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make sure the cam is not 180 degrees off.. cam lobes should be facing back. i dont know if its the same on a 2010 but thats how it is on my 06

they are all the same , when it is TDC on the comp. stroke the lobes point back and the valves are closed and are in position to be checked for clearance , it can also be at TDC at the end of the exhaust stroke and the begining of the intake stroke , this is when the cam is on overlap and the valves should be open the same amount , a cam only needs to be a few degrees one direction or the other from center to cause problems

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can't even get it to pop pushing it. timing is perfect. have to check if there's spark. It has a new fuel pump. I'm guessing electrical. either spark or injector.

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