chain problem

[freewheeling frank]

had the chain on my 4 stroke kinda double up on the drive sprocket and hit the engine case. broke the key on the final drive gear. had mr rights new and improved tensioner on it and seemed to be working great, any ideas? not enough oil on the chain maybe or are these chans just prone to this kinda stuff? later frank

 

[2door]

Sounds like maybe your chain was just a little loose. That will allow it to 'wrap' at the drive sprocket. Shoot for anywhere around 1/2 to 3/4 inch slack in your chain measured in the middle of your chain span. That should eliminate any chain problems you're having.
Tom