Less than 2 years ago I bought a mower from you, lately the mower seems to be down on power.
Under load the engine is blowing small amounts of black smoke. I checked the oil level & it is good.
When I removed the spark plug, it is very black & sooty, not oily.
When idling the engine has a noticeable "miss", that seems to settle under load.
It would seem to me that the engine is running too rich.
Are there any adjustments that I can make?