I have a LX277 with about 300 Hrs, lately when I start it after it is warm or when I engage the PTO it blows a puff of black smoke. I changed the plugs and they were very sooty. Any ideas?
Rich runner. Lack of air or excessive fuel.
1.Agree on looking at air filter and valves.
2.Carb needle needs pressure testing.
3.Pull the oil dipstick and smell for fuel.
4.Pull engine shroud and clean cooling fins and block - YEARLY. This is a must do maintenance item in yours and ALL other engine manuals.
5.Carb float level needs inspection.
Is this a one ignition coil firing 2 plugs engine? If so might have a weak coil or coil ground issue.