Too much oil in the crankcase will cause the oil to slosh up into the firing chamber and foul up the spark plugs.
Yes, it sure will. Never overfill your crankcase.
Putting too much oil into any motor increases the pressure in the crankcase,and can blow seals and gaskets.Draining oil to suitable level is strongly advised.
It is likely that the crankcase was much too oil. It is likely that the engine would have been damaged if the oil had not be changed.
The most common place for oil leaks is the sump/crankcase cover gasket. A torn gasket will allow oil to escape. A common cause could be a blown head gasket putting too much pressure in the crankcase.
the valves or rings are allowing compression blow by to enter the crankcase which causes excess pressure that is brought to the carburetor by the breather tube. your engine is getting tired or you have too much oil in the crankcase.
there is a problem with the PCV (positive crankcase ventilation) system. this system circulates crankcase air and oil particles in the air back into crankcase by pushing them back somewhere back through the intake. there is probably a problem with the PCV valve stuck open allowing too much oil to pass through it subsequently collecting on your air filter.
Too much crankcase pressure or the breather pipe is split/dosconnected. The crankcase breather goes into the rear of the air filter and the crankcase gasses are drawn in to the cylinder with the gas/air mixture and burned
One reason could be an extremely worn engine, another possibility is way too much engine oil has been put into the crankcase.
Too much fuel being put in the engine and it gets by the rings and if it has a mechanical pump attached to the motor, it can be leaking inside and running into the crankcase. Too much and the oil will be so thin that it no longer lubricates and you loose a bearing.
If there is oil coming from the exhaust manifold it generally indicates a bad valve stem seal or a worn out engine. (too much crankcase pressure)
combustion pressure will leak into the crankcase, and oil from the crankcase will leak into the cylinder.