HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
onebadyz450

Hinson Clutch and backfiring

3 posts in this topic

I just installed a hinson clutch basket and rebuilt my top end. After putting the basket in I notice a funny noise when the clutch lever is out. I pull the lever and it stops. Is this normal or do I have a bearing or something going out. Plus after I redid the top end the bike has started to backfire I adjusted the fuel screw and it is not as bad. Do I need to fine tune the fuel screw or is the timing off? I dont think it the timing because it still runs, but I am not 100% sure. Please help me if you can.

Share this post


Link to post
Share on other sites

Mine did the same thing when it was brand new. The noise went away after a few rides and the engine returned to its normal sound.

I wondered if the tolerance on the clutch hub bearing was different. I changed the bearing but it made little to no difference.

Share this post


Link to post
Share on other sites

Most 4-stroke singles will make a growling, rattling sort of noise with the engine idling in neutral. That's because the engine doesn't really spin at a steady speed, but accelerates on each power stroke, and then suddenly decelerates at the next compression stroke. This gets transmitted to the transmission via the clutch and the whole thing rattles and grumbles. Normal. If it will go away when you speed up the engine or pull in the clutch, there's no problem.

There are two common causes of exhaust decel backfire. One is lean idle mixture. If this is the culprit, you should be able to clear it up by backing out the fuel screw 1/4 turn. Don't adjust idle to the point where the engine runs wrong just to clear up a little popping noise.

For more info: http://www.thumperfaq.com/jetting.htm#PJ

Cause number two is an air leak at the mid-pipe joint or the header/head joint, or elsewhere in the exhaust. Tighten the clamp if there is one, and check the joint at the head. Don't worry too much about it, though. If there doesn't seem to be a fire hazard, and it isn't so bad that you think it will blow your muffler off, it won't hurt anything.

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

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
Sign in to follow this  
Followers 0