My mother's lawnmower was smoking a little on startup. I mixed in some seafoam with her gas to try to clean it out.
It no longer smokes but now it has this odd behavior. When you start it up and it's cold, it runs perfect. Then slowly, as it warms up, it starts pulsing. Not quite sputtering, not quite surging. Just inconsistent RPMs.
What would cause that kind of behavior?
Without knowing the model of this mower I am just guessing. My first thought is something is partially clogging the fuel flow, and the inflow into the carb isn't keeping up with demand.
