2007 m8 help

[waynemags]

riding today in fernie. everything goin good. rode up hill behind new cabin , played around for a while, all good. i get to top and shut my sled off. wait for bro in law to get up there with my spare m8. he pulls up beside me and shuts it down. no issues no backfiring or bogging. go to take off 10mins later he pulls the cord and its stuck. wont pull. i grab front clutch and turn forward and locks up. turns backward ok. turn forward again and locks up0. had to tow it out. take exhaust off and inside of ypipe is all grey colour. not black or oily like i thought would be. pistons seem to move up and down ok. untill it gets to spot where it locks up. anyone have any idea where to start? i was thinking powervalve stuck in. maybe. or bearing gone but assume it wouldnt move either way if that was the case. maybe conrod? need your thoughts.

 

[moyiesledhead]

That grey colour is most likely aluminum, or at least the inside of the Ypipe burned clean by a lean condition. I'm betting you squeeked a piston. Should be able to see the condition of the piston skirt & dome through the exhaust port.

 

[waynemags]

be a couple weeks before i get home to tear it down. i thought same thing as well. thing is it wasd running perfect. no overheating, no bogging, no odd conditions. pulled up shut down had a smoke and went to start it. no pull. can turn it backward but it seems to get to a spot turning forward and stops.

 

[moyiesledhead]

Ya, mine usually run great just before they melt too!

 

[waynemags]

hahahaha true enough.