Is it gray colored smoke or black. As in a rich sputtering choke on like condition?
Is your plug oily or black carboned up?
You do know on that bad azz engine, you only park the dipstick on TOP of the threads while checking oil level right? Briggs engines you screw all in. Most other brands you park. If you are screwing all in, you will get an incorrect oil level. As in you will be under filling the oil.
Carb linkages fauled up.
Dirty carb and sticking open needle/seat.
Pull dipstick and smell for fuel. If you smell gas in your oil, repair carb needle/seat then DUMP oil and filter a couple times.
Some good things to start with below.
1.KEEP and remove OEM carb from engine. Break it down removing all small parts. Boil clean the carb on your stove top with water and those automatic dishwasher balls. Use a candy thermometer to keep water/soap temp at 200F. Boil for 30 minutes. Rinse well in clean water to neutralize after. Reassemble carb. Flip carb over and blow test carb needle/seat (fuel inlet pipe). Should hold 7psi for 30 minutes.
2.Remove fuel tank. Clean out 100% with compressed air. Install new fuel line, filter and shut off valve if you have room.
3.Clean block and cooling fins YEARLY per your engine manual. Remove top metal engine shroud exposing cooling fins. Neglect this and you will get engine damage.
4.Adjust valves per your engine manual yearly.
5.Decarbon cylinder and valves every 5 years or suggested interval in your engine manual. Neglect this and you will get engine damage.
6.Test ignition coil with old spark plug gaped to 0.250" or 1/4". Check for good blue spark. Check for spark if and when engine dies with inline spark tester.
