2004 kx250f not starting practically new

[mrdrummer1818]

so i recently bought a 2004 kx250f i have been working on the bike my self i am very new to dirt bikes this is my first one so i apologize in advance if it is a simple fix. i have redone the top end new valves and i have a new spark plug a clean carb and a new air filter all the normal stuff that needs to be changed has been like oil and antifreeze. the timing is correct and so are all the valve clearances. yet when i try to start it it never comes to life i tried to run start it and the back tire locked up and skidded across the pavement i looked in the carb and the gas had a yellow color to it but if gas is not the problem what els could be causing it to not start.

 

[Ol'89r]

Locking up the rear tire is an indication of the cam timing being off. Recheck your cam timing.

 

[RMZ450FIRST4T]

That was my first thougt also, cam timing. Your piston is pushing against you valves that are open while piston is at or close to tdc. In what gear did you try to run start it, on what surface (how much grip does your wheel have)?.

 

[mrdrummer1818]

thanks guys i will recheck my timing again tonight and let you know

 

[mrdrummer1818]

yep it was 180 degrees off i used the wrong timing lines on the fly wheel thanks guys for your input