Another great modification for the Homelite 25 is to send the piston to Frank Bowman and have him install a pin in the ring land and make you a ring for pinned use. Then you can grind out the bridge in the exhaust port for MUCH better flow because the ring won't be able to turn and get caught in the port.

A Homelite 25cc I did for a friend has the 11mm carb, a free flowing muffler, the base gasket left out to raise compression, and the above modification. With no porting or other hop ups it turns a 15 x 8 APC prop at 9400 rpms. It will turn a 16 x 8 at around 8700.

AV8TOR