I have been playing around with mini bikes, etc for quite a while now, but my rebuild of my Trail Horse is my first experience with a new centrifugal clutch. I fired it up today and all seemed well, except the almost solid sounding bang coming from the area of the clutch. I thought the free turning chain was hitting something, (rear wheel is suspended). I shut it down and again checked the spin of the rear wheel. Nothing. No catching anywhere, no banging, nothing. So, is it common for a new clutch to, "grab" and skip/stall until it gets broken in?
New Centrifugal clutch.
- Thread starter bikesisbikes
- Start date
No swing arm, rear wheel is new and the bearing is tight. Mounting bolts are new and tight. I did back the engine off about 1/4 inch. I backed the engine adjusting bolt off about 1/4 and then one by one loosened the engine mounting bolts and allowed the engine to slide back against the adjustment. This seemed to help, a little. So maybe it is just a matter of the chain being too tight. I can't really tell any difference in the chain deflection, but it has to have some, since the engine has moved back.
I have made several attempts to create a video but all have failed. Even when I know the banging occurred, while I was videoing, it doesn't come across. The bang is barely perceptible. What the video does show, is a lot of jumping and dancing of the chain. While videoing, it sounded like the chain was actually jumping or skipping on the sprocket. The problem there is, it isn't that loose. In fact, it's not loose at all. One thing I did notice, it goes away as I rev the engine.
Oil your chain (that's an exercise in constant maintenance since it always gets flung off) and oil your clutch bushing with a couple of drops of motor oil. Below is a great guide:
10 Things to Know about a Centrifugal Clutch
10 Things to Know about a Centrifugal Clutch
I’ve had the master link hit the clutch before, believe it or not. This was with the clutch sprocket facing the engine, and the master link clip facing out (towards the clutch). I’d pretty much get a small clunk every time the chain came around as it rotated. Flipping the master link so that the clip was opposite the clutch (towards the engine) eliminated the problem. Easy enough to look and see if it’s hitting.
As I said in the initial post, everything in the drive line is new. I don't disagree, that lack of lubrication should be the cause, however, that is all I did and it seems to have cured the problem. The chain was shipped dry, (ie, not wrapped in plastic with gobs of oil everywhere). My fault for not lubing after I sized it. I have always used a light coat of graphite impregnated chain oil, on every other project. It has worked on some pretty nasty looking chains. After i get a couple hours run time, I'll take it off and give it a thorough check.
I thought about that, but there is no apparent contact, either with the chain or the clutch housing. For now, I just have to believe the dry chain was binding on the smaller sprocket. Or, there may have been a stamping burr on one of the links. So far, since the lube, I haven't heard anything and the operation seems to be smooth.