Why is my lawnmower smoking black smoke? I changed the oil and the air filter? what gives?
Answers:
Black smoke is definitly worn rings. Check your spark plug. If it is black and carbon is building up it is a ring problem. A rich gas mixture will give dark smoke but will not foul up your spark plug as quickly as rings.Only have rings replaced if your engine is a large expensive one. Repair requires complete ripdown of the engine. $$$$$ White smoke is caused by over filled engine block or tipping mower on it's side. NEVER DO THAT! Only tip a mower so that the spark plug is straight up so oil goes to the back of the block.
Other answers:
did you spill some oil on it?
did you spill some oil on it?
Maybe you can wait until it stops (5-15 seconds)
Did you spill Gas or even Oil anywhere on the engine? If so, it may take a while to burn off.
you probably put it too much oil...try draining some of the oil...
Did you add the proper oil in the proper amount? Usually it is a result of too much oil.
gas oil mix or bad valves or bda cam shaft
Oil is getting down into the combustion chamber. ie your engine is worn out. Take it to a LM shop and they might be able to rebuild it for u
Is the combination of gas and oil correct or are you filling it too full? It also may need to be cleaned out underneath around the blade, wet grass and dirt collects.
If it's a 4-cycle and blowing blue/white smoke, there is too much oil getting into the combustion chamber. There are several causes for this, and among them are worn rings/cylinder/piston, as well as too much oil in the crankcase, wrong viscosity oil and very old oil. All 4-cycle engines have a crankcase breather of some type that carries blow-by fumes back into the intake side to be burned, and there could be a problem with that system.
If it's blowing black smoke with some blue, it's getting too much fuel. 2-cycles usually only smoke excessively from too much oil in the mix or too much fuel getting into the engine. 'Coked-up' rings can cause this in a 4-cycle, and there are engine-cleaning solvents available that could free the rings.
Simple rule of thumb is black is rich (too much fuel) and white to blue smoke is oil.
What it sounds like (you've already changed the air filter, so thats not clogged up choking it out) is that you may have some trash in the carb, before that though...... has anything been tampered with on the carb? Does fuel want to leak out everywhere? Just to rule out a mis adjusted carb, and a inlet needle or float problem. The butterfly/s in the carb operated freely (of course connected to the linkage) but do move freely?