Re: This Motorized bike thing is the cats pajamas
Make sure your engine is mounted solidly to the frame with absolutely no movement in any axis. Your chain/sprocket alignment is also critical and if off can cause the chain to run rough. A chain that is too tight or too loose will also contribute to your problem. 1/2" to 3/4" of slack is generally the recommended tension.
You might also want to remove the chain and inspect it carefully for any twists or kinks or binding rollers or side plates. Some kit chains are notorious for these faults and will never run true or smooth over the sprockets. Sprocket teeth can also be rough which doesn't allow them to smoothly engage the chain. Lubrication is also important. A dry chain won't run smooth. Lots of options there as far as chain lubricants.
Good luck. Let us know if any of our suggestions work for you.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"
Last edited by 2door; 08-07-2013 at 11:11 AM.