Which issue can lead to an engine overheating?

Improper carburetor adjustments can significantly affect engine performance and lead to overheating. The carburetor is responsible for mixing air and fuel in the correct ratios that the engine needs for combustion. If the carburetor is not adjusted correctly, it may lead to an excessively rich or lean fuel mixture.

An overly rich mixture provides too much fuel for the amount of air, which can create incomplete combustion and excess fuel might not evaporate properly, causing the engine to run hotter than normal. Conversely, a lean mixture means there isn't enough fuel to cool the combustion process, resulting in elevated temperatures. Both scenarios can strain the engine and lead to overheating conditions, potentially causing severe damage if not addressed.

Other factors, while they can also contribute to engine overheating, do not have the same direct impact as carburetor adjustments. For example, excessive fuel in itself does not always cause overheating unless it leads to combustion inefficiencies. Air filter blockages primarily affect airflow, which can also influence temperatures but indirectly compared to improper fuel mixtures. High ambient temperatures can increase engine operating temperatures but are a more external factor that does not change the engine’s inherent operations.