I have a K & B .61 Twister and it is an awesome powerful motor. It turns a 13x6 Master Air Screw Simitar prop with authority. I've quiet a few K & B engines and I've had very good luck with them for over 30 years. The K&B Sportster series are all very good running engines and run them all on one model or another. Inexpensive and good running. And if you are lucky enouh to have a C.F. Lee reworked K&B, you are in for real surprise.

Soft landings always,
Bobby of Maui