Wouldnt that also act as flywheel? If its lightened too much, would you be forced to jack the idle up? I wouldnt do more than lighten it w/o a nod from someone with firsthand experience.

You can ditch it, atleast in the 2 cyl I know of ... and the thing will spin up crazy fast, but you have to balance the crank and even so, it shakes like crazy except in a small rev range, like between 7-9K it will run acceptably smooth. In fact balanced the right way the guy said it was buttery smooth ... better than stock in that range.
Cool.
Srinath.

I will look into this more before I do it.... and with this heavy'r Chevy piston.... if I can make that work may help it or hurt it 2x !

Well I.m not going to take the chance and keep it.... I would try it with out first but I just dont want to bust open the cases again to reinstall it...

And that Chevy piston is now just a shelf bit... well unless someone would send me a jug and head to try and make it work but the jug would need spacing up close to half an inch, so a longer cam chain and not using your head to frame mounts would be required...