Jump to content
Sign in to follow this  

Help 2008 crf450 popping and backfiring

Recommended Posts

Hi guys, I just bought a 2008 crf450r. It had been sitting for a while wouldn't idle with the choke off and it sounded like when I gave it throttle the the rpms would stay high for a minute then come back down. I decided to clean the carb and check the jetting. I left all the Jets the same except I seated the pilot screw then backed it out 1 5/8 turns. Started it up and now it's popping and backfiring, after about 8 minutes of idling it puked up antifreeze. My buddy thinks it is lean. Any advice?

Share this post


Link to post
Share on other sites

Put in a NEW pilot jet

Clear the passage above the pilot jet with fishing line and spray cleaner

Inspect the fuel screw oring

Inspect the hot start for coorsion (not sealing, and leaking)

Share this post


Link to post
Share on other sites

The exhaust wasn't tightened enough backfiring has stopped. The slide facing the air box is slightly open and opens all the way when you give it throttle. I didn't see a hole on it. it still pops and crackles a bit when it's on the stand and I rev it but riding it I didn't notice it happening.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

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

Reply with:

Sign in to follow this  

×