The camshaft on the engine was damaged, so I replaced it. This mower hasn't ran in a year or two. It has a small pulsa carb. When I start the engine the engine surges. I can see the throttle/governor linkage moving back and forth while it is hunting. I cleaned the carb a few times with carb cleaner and compressed air, and it still surges. The governor spring looks a little stretched. Could a stretched governor spring cause this issue?
