Chain bound up in fromt sprocket

J

Jsmith

New Member
On my 80cc motorbike the chain keeps geting bound up in the front sproket. We get it up to speed and let off the cluch and it gets bound up right away. an idea whats happening??
 
Post some pictures of how you have it all set up!

Also... the rear sprocket being bolted on 'off center' will cause the chain to go 'loose-tight-loose-tight' as the rear wheel turns, & that will also cause the chain to bunch up at the front sprocket. :/
 
Last edited:
Venice Motor Bikes said:
Post some pictures of how you have it all set up!

Also... the rear sprocket being bolted on 'off center' will cause the chain to go 'loose-tight-loose-tight' as the rear wheel turns, & that will also cause the chain to bunch up at the front sprocket. :/
Click to expand...


+1..

either out of alignment or off center.
 
take the cover off & spark plug out & watch the chain - you may have to file or grind some of the sprocket teeth to make them pointier both front/back & sides
 
Jsmith said:
On my 80cc motorbike the chain keeps geting bound up in the front sproket. We get it up to speed and let off the cluch and it gets bound up right away. an idea whats happening??
Click to expand...
If the chain has the proper tension, and everything is in good condition, and it continues to jump off, then the chain rings (sprockets) are misaligned in one dimension on another.
Expose everything, and try to get it to happen in slow motion.

There is always an explanation for mechanical events.
 
this is a serious thing,as you already know the wheel locks up and bike comes to an abrupt stop.
second part of this- the housing around the chain,breaks off.mine broke the magneto housing as well as the clutch lever housing.pretty much demolished crankcase.

make sure the wheel sprocket runs perfectly true,side to side and up-down.
straight edge from sprocket to engine sprocket,making sure its very close.
chain tensioner need be adjusted correctly,using minimum amount of chain.

some here have good success eliminating chain tensioner altogether.
i had a little issue with chain rubbing tire,it was a little too knobby on the sides.i think this was part of the cause too.
 
The front sprocket needs the teeth filed or groung a little to free up the chain. I've run into this on a couple kits. Also make sure the sprocket cover is not binding the chain. One kit I received was so bad it sounded like sticks breaking when the chain pulled on and off the sprocket teeth. Just knock the corners off and round the tips a tiny bit. and see if this helps.
 
You must log in or register to reply here.
Back
Top