well, the OS is an awesome engine and makes a ton of power. They start right up and hold a tune forever. However, you will be transferring addition power through the drive train, so if you womp on the gas you run the risk of stripping your plastic spur gears or breaking dogbones.

I really liked the Smartech engines. I had 3 of them and never had a problem with any of the engines themselves. Only had a OWB in the pull starter die on me. Other then that, I liked them. They were a little low on power compared to others, but they ran great.