I have a Bolens G 11 with an 11 hp Briggs horizontal shaft that smoke like a banche. Haven't run it much so not sure where the oil is getting into the cylinder at. I my add a cup full or so of the Lucas Oil Treatment to the oil and see what that does. MMO in the gas, strong shot won't hurt either. Will try about anything before I tear it down. Sure want to save it being a horizontal shaft and 11 hp. Anything that size and up is getting real hard to come buy. Lot of horders out theree that are buying up all they can find, especially Wisconsin and Kohler hoping to strike it rich down the road.