2005 CRF 450R issues

[CRForbust]

Hello,

 

i recently bought a CRF450R, i am currently having issues with the bike not starting. it was sitting for about 6 months.

so far, i have replaced the spark plug, drained the float bowl of the old gas, and drained the old gas out of the gas tank. 

i cannot kick start the bike, but i can pull start it. when i do get it going i cannot get the bike to idle, i have to constantly give it throttle or it will die, and when it runs it constantly back fires, i have been told it could be valves, and also been told i need to rebuild my Carb.

[brendan31]

I would start by pulling the carb off and cleaning or rebuilding

[CRForbust]

Okay, thank you. Do you think it could be the jets? 

 

[brendan31]

Yes very well could have gotten clogged with some varnished fuel from sitting

[jblob]

I agree with the above. Replace the main and pilot jet just because they are cheap and easy. Narrow down the list but that'd be my first guess. The pilot hole is TINY and easy to clog and if it doesn't idle it's clogged up and you keep it running with bursts from the acc pump and main jet

If it ran and started fine when you stored it your valves wouldn't have wandered out of spec sitting a few months. 

[brendan31]

Make sure if you replace you get the right jets for your elevation