Yamaha 15 hp , 2 stroke , shaving head

Would like to know the max. I can shave the head of that little 2 stroke , 15 hp engine .. using 93 octane non ethanol gas .... Thanks

1st thing to do is check the squish. This will give you an idea. That would be a simple shave. Now regardless of squish you can shave and re-chamber it also. That process is much more involved.