I have two engines, one is an O.S. 35cc, and the other is a McCulough 46cc chain saw engine. I had to buy a Sullivan starter for $100.00 to start them. The pull start is much easier and the CY engines are pretty strong. Some of the Cajun Gator boats run modded CY's but I'm not sure they are worth the trouble. They have shattered props and bent crank shafts with them. Probably too much torque and they may rev up too fast for the Master Airscrew props. I personally prefer the APC two and three bladed props. Dennis