Sorry about the long winded title but I want it to catch someones attention who might have the right answer. What could this be. Bad crank, bad drive/driven clutch, I should also note that there is also a vibration in the left running board/bars which kinda scares me. hope the drive shaft isn't messed up. could it simply be a bad bearing on the jack shaft or drive shaft speedo side? . Check the chain the other day and it was fine. Also I should note that when I blew the belt it didn't completly let go, only half of the top layer came loose. Just looking for a few educated and informed opinions/answers.