It starts first pull and runs well. Compression is about 105. Did a leak down test and it has very low leakage (around 5% or less) based on Harbor Freight tester. It started smoking quite a bit this year and it is unknown age but likely 10-15+ years old. Plug is black with soot. With 105 compression and seemingly low leakage what may be causing the smoke?
Depends on the color of the smoke.. Blue smoke would indicate oil burning which could be overfilled. Black smoke would indicate rich running like either a leaking carb or even fuel in the oil. And both conditions can develop if the air filter has been wet with anything including water, oil, gas. So may want to try a new air filter and see what happens.
I don't smell any fuel in the oil. I have never checked the valves as it always ran great. It isn't used much anymore, just to do the edges where the zero turn can't get. I am going to try a new air filter.
