I would think cranks can also be balanced so it will run smoother @ high RPM & run a little rough in the lower RPM range.
I'll ask Dave @ "The Balance Shop"
When I used to road race a two stroke GP bike & other 2 stroke engines,I keep on breaking cranks because the class made us use the stock heavy flywheel.
I had my friend Dave @ The Balance Shop ,balance the crank so it would run smoother @ high RPM ,,& it did just that,a lot smoother & just pulled cleaner all the way up to 13,000 RPM,eventually the crank still broke,but it did last longer than w/a stock crank & with stock/original balance.
Originally the engine turned to 8500 RPM,& the crank would last a full season.
MBHD
Hank, thats called "over balance", we did it. Winston Cup and many race classes that have engines that run in the high RPM range like that also have done it for 20 years or so. It definately helps. Its easier to do on engines that use bobweights to balance them, because you just cheat the bobweights by the amount you want to "over balance" it. On an inline that doesn't use bobweights, its a little more difficult, but it can be done.
