Oooops...too late! Tore it back down today and pulled out the crank. I also verified my balancer assembly was lined up properly with the crank, though the machine shop also slightly messed up my counter balancer when they replaced the bearing on it. The balancer gear is now pressed on slightly off from the timing mark (that goes across the shaft and gear) but it's only off by the width of the stamped in punch line. Even with that slight miss-assembly I still think my crank is perhaps the main vibration culprit. However if the shop verifies my crank is already true I'll revist the counter balance gear install. That said today I also learned that it's possible to pull the crank without removing the clutch and shifter assembly so that did speed up the process. I had the engine out of the frame and the crank in my hand within about 90 minutes, including zip lock bags labeled where each bolt goes. That said, not sure who I'll have check and true up the crank but I bet it's off. Yes it is a buzzy little engine, but in the last couple rides I've noticed my fingers going numb much more readily then before the rebuild so I still have a little more work to do until it's 100%. Other than the slight buzz increase the bike is running great, I got 55mph the other day on a mild downhill. (edited)