What is the most likely cause if the engine starts but only runs for a few minutes?

When an engine starts but only runs for a few minutes, a slow or irregular fuel flow is a highly plausible cause. The engine relies on a consistent supply of fuel to maintain combustion. If the fuel flow is insufficient—perhaps due to a clogged fuel line, a dirty fuel filter, or issues with the fuel pump—the engine may start initially but will not be able to sustain running for an extended period. This situation can lead to the engine stalling as it runs out of fuel.

The other options present different issues that may affect engine performance, but they typically do not explain the specific scenario of starting and then stopping shortly after. A clogged air filter might restrict air intake but usually would prevent the engine from starting at all rather than running briefly. A stuck choke could lead to running problems but often results in a rich condition that might cause the engine to sputter rather than run for a few minutes. A worn spark plug could cause misfires, but it’s less likely that the engine would start and run smoothly, even for a short time, before failing. Thus, the most likely cause in this situation revolves around the irregularity of fuel flow.