2011 yz450f half kick then stops

[lkirsch2011yz450f]

I had been riding and had to lay my bike over to help a buddy and when I picked it up tried kicking it and got about half crank out of it and it stopped dead. Coulple days later I had to

Move it and had it in gear by accident and it turned back and then I could get a stroke out of it again before it would stop again.

Haven't pulled it apart but the only thing I could think of is if it somehow skipped on the timing and it is hitting a valve.

Anybody got any other suggestions?

[Powerage]

Others will prob have more of an idea, but just wanted to post that i have a 08 WR450 and mine will sumtimes lock (both kickstarter and electric starter unable to turn over engine) up like you describe when ive stalled out on the trails. Usualy just rocking the bike backwards whilst in gear is enough to 'unlock' it and will fire up right away. From what I read it could be just the engine stopping at TDC and also have seen somewhere that maybe installing a hotcam is a way to fix problem from happening, but its never bothered me too much to look at going down this path.

Edited June 15, 2016 by Powerage

[grayracer513]

Haven't pulled it apart but the only thing I could think of is if it somehow skipped on the timing and it is hitting a valve.

Anybody got any other suggestions?

 

That's probably it.

 

 

Others will prob have more of an idea, but just wanted to post that i have a 08 WR450 and mine will sumtimes lock (both kickstarter and electric starter unable to turn over engine) up like you describe when ive stalled out on the trails. Usualy just rocking the bike backwards whilst in gear is enough to 'unlock' it and will fire up right away. From what I read it could be just the engine stopping at TDC and also have seen somewhere that maybe installing a hotcam is a way to fix problem from happening, but its never bothered me too much to look at going down this path.

 

Yours is different, and a Hot Cam won't fix it.  What happens is that occasionally the engine may stall abruptly just as it reaches a compression stroke, and this may stop the engine more quickly than the auto decompression setup can reset.  That results in the same condition you'd have without AD; you have to kick through the full compression stroke instead of the greatly shortened one the AD unit usually provides.  Without a manual decomp lever, your escape is to back the bike up in gear just a little way to allow the decomp pin to extend, and then it kicks over normally.