2003 yz 450 help!!!

1 reply to this topic
  • custmrylstr

Posted November 16, 2010 - 11:35 AM


het guys nub here and i got a question for you experts out there.
Heres my dilema,
I took my beauty 2003 yz 450 out for a last ride of the season before i pull the sleds out and everything was perfect until the ride home. basically the bike shut down after about ten minutes of riding (had stopped for a while)
seemed to run out of gas, so i tried to kick it over she kicked about 4 times fired up and then stalled out again, the thing is I couldn't kick it over anymore, it seemed as if I blew it up locked up. started tearing into her and found a mouse had got into my airbox and ate the outer layer of my filter ***!!
pulled the plug out and it looked perfect i moved the kick starter by hand and evrything seems fine did a compression test on it and it was in spec according to the book.

long story short kicker locked up found mouse ate my filter plug looks fine carb full of s*^t, also I broke my decompression lever a while back and never replaced it. is it possible that there was just way too much compression to kick it over and it really isn't blown up?? is it possible jets got so clogged that bike wouldn't start and shoulhave had my decomp hooked up??

sorry for the novel just trying to give you as much info as possible

thanks in advance for all your helpful input!!

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  • grayracer513

Posted November 16, 2010 - 11:50 AM


If you have an '03 YZ450, you never had a decompression lever, for one thing. Your post is confusing because on the one hand you say the starter is locked up, then you say it was fine with the plug out, then say it's locked up again.

Assuming the starter assembly is OK, check the cam timing. Having the chain slip on the exhaust cam can cause the decomp unit not to work effectively on top of preventing the engine from running.

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