What will occur if more oil is added to the fuel than specified by the manufacturer of a 2-cycle engine?

When more oil is added to the fuel than specified for a 2-cycle engine, it leads to increased carbon buildup and engine fouling. This occurs because 2-cycle engines mix oil with fuel for lubrication, and an excess of oil in the mixture results in incomplete combustion. The surplus oil does not burn off effectively during the combustion process, leading to the formation of carbon deposits on critical components such as the spark plug, exhaust system, and combustion chamber.

Over time, this carbon buildup can cause the engine to run less efficiently, potentially leading to misfires, increased emissions, and a host of performance issues. Therefore, adhering to the manufacturer's specifications for the oil-to-fuel ratio is vital for maintaining engine cleanliness and ensuring optimal operation.