Small Engines (Lawn Mowers, etc.): Lawnboy 4.5 hp 4 cycle engine, air cooled engine, mains

Question
I have a Lawnboy that doesn't want to keep running until it warms up. The engine has a primer and no choke, and when it starts it is at running speed, rather then being able to let it warm up at lower speed like the older engines were built to do.Any ideas on why it keeps stalling until it warms up to operating temperature? Thank You

Answer
Who ever told you that an air cooled engine should be warmed up at idle before you use it. The biggest thing you are battling in an air cooled engine is HEAT. You want that engine to run as fast as it will run from the moment you start it until the moment you shut it off. WIDE OPEN all the time. The engine actually runs much hotter at idle than at WIDE OPEN. Air is forced across the cooling fins by the flywheel fan. Faster it spins, cooler the air.

You need to clean the carb. It's full of crap left over from last year.
Who ever told you parts need to expand so they don't bang together is smokin crack. The only thing that keeps parts from banging together is oil. The way to get the most oil to the rod and mains is to spin that sucker as fast as it will go.