They are great little motors and can stand terrible abuse. I had the throttle on mine permanently wired wide open since it drove a water pump that loaded it down to a steady 3,300
rpm. It ran with 100% throttle, 100% load, for the lifetime of the engine. When it would occasionally lose suction and race with no load, the reed valves floated and limited
rpm. This didn't seem to hurt it.
I finally killed it (actually, just reduced the compression so it was hard to start) when I grabbed the wrong can and ran a whole gallon of Coleman fuel by mistake. That's the same thing as Stoddard Solvent, the stuff for washing parts, so it ran for 2 - 3 hours with no lubrication whatsoever. I think a set of rings would have restored it but I already had a heavier Briggs engine/pump that I put in service.