Had the same problem. Threw on a new chain and it was a little better. I tightened the chain a little and after I ran it a couple races it freed up more. It drove me nuts trying to figure out what was going on with it. The bully instructions also tell you to sand the inside of the driver lightly with 600 grit sandpaper. I took a paddle wheel sander on a die grinder and honed the inside of the driver out really good. Bully says to use a small amount of HD wheel bearing grease on the driver, but I found that silicone grease works best. Just go light on the grease.