engine running very lumpy (with some black smoke) misfire continues then often clears and runs sweetly. two years old with little use. with my limited knowledge I think the problem my be a mixture problem

norman ainslie, July 2008

Will be the carb diaphragm. Will need to remove the carb/tank assy, and then split the carb from the tank on a bench. Clean up the two halves and replace the diaphragm and gasket (comes as a kit from Briigs). Re-attach carb to tank- making sure you tighten the screws evenly and then re-attach to engine.

pleasant, July 2008