This dont sound right..

[416exfreak]

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Engine suffered an unknown failure today while I was running some practice laps.

Anyone got any ideas?

Still pulls hard. Runs fine, just sounds like hell.:(

[sturdivant58]

cam chain tensioner broke!! I would recommened not starting engine untill u replace it!! You can and will jump time and bend valves!!!:devil:

[416exfreak]

Originally posted by sturdivant58
cam chain tensioner broke!! I would recommened not starting engine untill u replace it!! You can and will jump time and bend valves!!!:devil:

Nope, I already pulled the tensioner. Thats what I thought it was at first, but the tensioner is completely 100% ok.

:confused:

yeah i think something is slapping around inside the motor. Try the tensioner, I would take it apart and look like said above before starting it again. Awesome quad by the way

[416exfreak]

Originally posted by FoxHondaRider
yeah i think something is slapping around inside the motor. Try the tensioner, I would take it apart and look like said above before starting it again. Awesome quad by the way

Thanks for the compliment!

But I've already checked out the tensioner. Its fine.

Im stumped. I hope its nothing to serious. Dad already said if it is, we're springing for an engine out of either a Yz426 or CRF450R and putting that in there. That would be early 16th b-day and if I can talk him into it, some FullFlight +2 A-arms for early X-mas.:devil:

[250x_kyle]

may be a streched cam chain or the crank could be going out.

[Kickstarts-suck]

check the cam sprocket bolts. Mine came loose before and it sounded like that

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[Shift_450R]

Could be the bottom cog that runs the timing chain on your crank. It sounds exactly like mine when it happened. Heres a pic of mine, it sheared of two teeth:ermm:

http://img.photobucket.com/albums/v312/kwiatkowski/Picture008.jpg

[ZeroLogic]

Originally posted by Kickstarts-suck
check the cam sprocket bolts. Mine came loose before and it sounded like that

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Ditto, same happened to my ol 300.