Hello, I recently bought a 1940s champion 4.2 hp blue ribbon outboard and I am having trouble keeping it running. Hoping someone can point me in the right direction of where to begin. The motor usually starts after a few pulls, and will run for a few minutes and then stop even at high rpms. Sometimes the rpms will get very low and i have to keep pressing and letting go of the choke to keep it running. Its confusing that it turns over reliably, runs for a few minutes and then stops. Any clues about where to start would be very helpful