YZ450F wont start, HELP!

I have a 2005 YZ450F and it was hard to start so i shimed the valves and they are perfectly in spec now, and im pretty sure the timing is perfect, the lobes are facing out and the dots are horizontal to the head. also the 2 dots are facing straight up and there are 12 pins in between the 2 dots. now i cant get it to start. i have nooo idea what to do now, it also has good spark. please help me!

Edited by motox318

... the lobes are facing out and the dots are horizontal to the head. also the 2 dots are facing straight up and there are 12 pins in between the 2 dots. now i cant get it to start. i have nooo idea what to do now, it also has good spark. please help me!

Should be 13. Check the other two marks again. One of them is wrong.

Also, make sure the crank is in the proper TDC for checking your timing.

Also, make sure the crank is in the proper TDC for checking your timing.

Misleading: There is no wrong TDC to set timing. The ignition fires on every revolution, so it makes no difference which TDC is used. If the cams appear to be upside down when checking timing, simply turn the engine one more revolution.

Should be 13. Check the other two marks again. One of them is wrong.

I've heard 12 and 13, problem is that its a factory bike so it has a different side cover and there is no 2 caps to remove to check the tdc from there, so that makes it a bit more difficult.

Shade tree mechanics way to find TDC, remove spark plug and insert a plastic straw into the spark plug hole and watch it move up and down until you find the uppermost part of the stroke. You should be able to move it slowly with the kick starter lever using your hand. Not exact, but in the absence of timing marks or a viewing hole should get you close.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now