The motor starts on first pull and runs great for about 10 minutes then it bogs down and shuts off and the flywheel won't turn. If you wait a little while it will start back up and run for a few minutes or if you turn the flywheel (by hand) backwards and then forwards it will start and run for a few minutes then shut down. The water pump is pumping water and I've put a new head gasket on the motor. I've also bought a new fuel tank and fuel line. Any ideas of what my problem might be? The motor # is N99B2. It had been setting up for about 3 years before I got it. I'm guessing it to be less than 10 years old with very little use. It is a 2 stroke engine. Any help would be greatly appreciated.