I picked up a small 15.9cc (0.97 cu.in) toro complete engine a while back. It has great compression. It looks like a scalled down 25.4cc toro. The bore & stroke are 26 X 30. It weights a hair over 4lbs. with the recoil starter, flywheel ign., clutch & housing, muffler. nothing trimmed. I doubt if I will do any thing with it. It could probably could be tirmmed down to two to two and a half pounds with EI ign. or gas/glow set up.