I recently bought 2 older simplicity lawn mowers(made by alice and chamers) both 11 hp, the difference is one is hydrostatic one is manual. on the manual one i rebuilt the carb, gave it a new fuel filter, added some oil, tuned the carb, adjusted the choke, drained fuel tank and gave it new gas, gave ot a lil seafoam and gave it a new sparkplug. Ran great. As for the hydrostatic did the same ****, carb flooded, replaced the float made sure the needle valve port was clean and stopped the flooding. it starts every now and then by luck. but it barely runs over 2 minutes before shutting off. it has great spark, and is getting fresh gas, so is it losing compression from somewhere? i removed the head and the gasket didnt look too bad minor wear on the inside part of the gasket. idk what else it could be, also when i excessivly try to start it the carb backfire smoke from the intake. please help thanks.:frown: