One thing I have found in altering 2 strokes is to raise the top of the exhaust port a bit, if the bottom of the piston when at tdc blocks the intake port at the top shave it off until it on longer is in the way, Polish everything to a mirror finish, all of the ports, inside the crankcase and what ever else you can see on the inside if the motor. An engine is nothing more than an air pump. The less resistance air has to get in and out will make it a more effecient motor