Chain skipping and getting stuck

GoldenMotor.com
Mar 16, 2016
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0
16
america
I have a basic chinese 2 stroke with a spring tensioner (the kind that's a lever and a wheel) that keeps the chain very tight..normally. Recently the chain has started occasionally skipping a tooth in the motor housing and then bunching up causing the engine to immediately die and the whole thing to lock up until i take the cover off and un-skip the chain. The chain is well lubricated and moves freely. It's also aligned well. It happens when the clutch is disengaged and I'm coasting, or right when I reengage the clutch. I'm sure that means something but I'm not sure what. Any help would be appreciated.
 

allen standley

Well-Known Member
Oct 22, 2011
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Bangor, Maine
Last edited:

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Get rid of that 'spring tensioner' and set your chain tension so you have 1/2" to 3/4" of slack. What you describe is exactly why spring tensioners aren't good for our applications. They allow slack when you don't want it.

Are you certain about your sprocket alignment? That is critical.

Tom
 
Mar 16, 2016
118
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16
america
unfortunately I have to have a tensioner because of the way the back fork is on my bike. The chain would be rubbing on the fork if there wasn't one That being said would going back to the solid tensioner be the next best thing? I never had any problems with that so I would assume so.
 

Chaz

Well-Known Member
Jun 3, 2012
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Vancouver, British Columbia
Like Tom said, the spring tensioner allows the chain to over-run the engine drive sprocket on deceleration causing the links to pile up in the casing. This can also happen at start up.

Definitely go back to the solid tensioner. And now you'll have a spare idler wheel.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
If you are relying on the tensioner to 'guide' the chain, that's part of your problem. The tensioner is a 'tensioner' not a chain guide. If your chain and sprockets are aligned properly the tensioner should not be dragging the chain to one side or the other for any reason. It is only to keep tension on the chain. Not to gain frame clearance or guide the chain onto the sprockets.

Tom
 
Mar 16, 2016
118
0
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america
It's not side to side clearance that is the issue. The tensioner raises the chain up enough that it doesn't hit the fork. I have an electric motor as well as the gas on the bike so it's placed differently than most. It's hard to explain but it is aligned.