Yep. I think there's 50, 28 and 0/internal. It depends on the bobweight and how much material is on the counterweights of the crankshaft. I'm a huge believer in internal balance on these motors going towards longevity, but it's a pretty expensive process.hmmm good info... stock there not internally balanced right? that's why the flywheel is (I think 50oz)? which I already have a new FR one ready to go on... with all new clutch stuff...
When balancing an external motor, it has to be done with the flywheel and damper/balancer installed on the crank, since those pieces make up part of the rotating weight.