8HP will not run when hot?

[Linescreamer]

This 84 Mariner 8HP 2 cylinder runs great until it gets hot. About 10 minutes running it just dies when applying any throttle. The filter has been cleaned and it has new fuel (no ethanol 91 octane). Carbs look clean but haven't been apart. What should I do next?

 

[jon-milford-ct]

Try running and spraying carb cleaner or starting fluid around the intake and if it revs up its got a leak somewhere and only opens enough to kill it when it gets hot and expands. You just have to be careful your not getting any in the intake openning

 

[MH Hawker]

Dose it have spark

 

[Silvertip]

When it dies, immediately check compression. Is the water pump working? An overheat condition causes the engine to lose compression and it will not run.

 

[racerone]

How can you say that the carburetor " looks clean " without taking it apart ??-----Is the water pump impeller in good shape / replaced recently.-----Have you checked fuel line ( O-ring ) for leaks , including the pick-up tube inside the fuel tank.

 

[undone]

It's very common for electrical components to fail once they get hot, so check for spark as soon as it stops. If it's overheating to the point of shutting down you typically have done enough damage that the compression would be low even when the motor is cold.


A weak fuel pump or an air leak in a fuel line can result in a similar problem.

 

[undone]

A weak fuel pump or an air leak in a fuel line can result in a similar problem.