engine at full throtel is surging the govenor linkage is moving in and out by its self. the engine sputters and you can see
blue flashes in the muffler housing. this engine is on a noma
(murray of Canada) snowblower with a tecumseh snow king
HMSK-80 engine. Is this engine's ignition solid state, or magneto? The unit is about 15 years old with about 10 hours of use per year. It never has been tuned up, just changed the plug every year and an oil change. Still runs and removes the snow but the engine rpm sounds slow. how do I get this engine purring again. Thanks,
mark

 

your carb needs to be removed, taken a apart, soaked and a new kit installed. You have varnish inside the tiny internal port holes.