Black smoke= running to rich(too much gas) try replacing your air filter or your carburetor might be out of adjustment, choke might be on
White smoke=burning oil. Make sure there isn't too much oil in the crankcase, use the proper grade oil- sae 30w. wore piston rings or scored cylinder wall. could be a few more internal engine failures.
The fuel filter is probably clogged and restricting the fuel flow. If the engine blows black smoke before it cuts out, then the engine is flooding - look for a dirty air filter or a fouled spark plug.
Worn piston rings. Incorrect weight engine oil. Gasoline mixed with engine oil. Crankcase overfilled with engine oil.
The engine is choking. Check (1) spark plug, (2) air filter, (3) carburetor settings.
White smoke is eaither a blown head gasket or you have water in the fuel system. This is not to be confused with flooding an engine and seeing white vapor coming out of the exaust in which that would NOT be smoke, it would be gas vapor's. If your burning oil, the smoke will be blue and smells of burnt oil.
My lawn mower smokes when it has too much oil in it or when the oil is watery. Try changing the oil.
IT IS BURNING OIL. YOU MIGHT HAVE OVERFILLED THE OIL OR THE PISTON RINGS ARE WORN OUT.
Black smoke means it's getting too much gas. Gas at the air filter also means that it's getting too much gas. The most likely cause it that the float valve is either sticking or has something stuck in it letting gas continually seep by it. Sounds like a good carb cleaning is in order.....
We need more info on your particular engine. It could be anything ranging from adding too much oil, worn piston rings, or the fact that when the engine is started, the carburetor is being choked (cutting off much of the air supply) causing the engine to obtain air from elsewhere in the engine such as the crankcase or through leaking gaskets, etc..
your engine is either too full of crankcase oil or you Are on the side of a hill too steep to operate engine on, or#3 YOUR RINGS ARE SHOT
Try cleaning or replacing the air cleaner. A clogged air clearner will make the engine run rich (like having the choke on). The rich mixture will cause the blackish smoke. The fileter may not even look very dirty, but the element can still be plugged and cause a problem similar to what you describe.
When you overfill oil in a lawnmower it will smoke when you tip it sideways while mowing,it has no harm
Yes, It will probably smoke due to the extra oil that is burning but will will work in a pinch. Not recommended for extended use.