trx 450

kinda hard to understand what your saying, but one thing you have to remember! dont everr touch the throttle when your starting it!
the carb has a pump that directly squirts fuel into the engine which will cause the bike to misfire and backfire and potentialy can kick back and destroy your starter.

you problem may be as simple as that.

it's a good possibility you have the timing of. lining up the marks can be tricky it's very easy to look at them at the wrong angle.

I'd recheck your timing. Also would check the decomp clearance again.

i have a 06 450r broke the decompresstion spring replace, lined the timing marks up on cam and gear put everything back together and it will not start back firers threw exhaust when u press the gas to start it ,its getting fuel and fire acts like it is still out of time could the marks be off some where,help please, eric thanks[/b]

Click to expand...

You lined the timing marks up on the cam and gear? The timing chain gear?
What about the crank? Was it still at TDC?