I bought a 150 last week to play with and after reading about the flywheel mod, I decided that I'd try it myself. I didn't lighten it as much as some people say you should in case I lost some of the bottom end grunt, but wow, what a difference it's made! When I get my hands on a spare flywheel, I'll fire up the Myford again and go the full monty.

I skimmed my mate's one down from the standard 117mm od 2.124kg to 100mm od 1.68kg, so that's just short of half a kilo or 1lb but can't say I noticed much difference, although I'm not what you'd call 'gifted'!

How much did you take off? I think Birks recommends 1kg but don't quote me on that.

Couple of 'after' photos, iirc the unmachined weight starts just at the bottom of the radius on the magnet rotor but I cant find any 'before' pics.

Edited January 5, 201412 yr by craig10

I took a little more than that off but I didn't take any photos either. IIRC the weight is a little larger than the rotor itself.