Small engine question

[GotOne]

I have a 18.5hp Briggs/Stratton engine on my lawn tractor. It seems to be running very hot lately (it's about 8yrs old). Any idea what I can do to make it run cooler or what causing it to run hotter? I never got an owner manual and I'm not to mechanically inclined. Thanks for your thoughts.

[Bobby Bass]

Change oil, clean or replace air filter- take an air hose an blow out under the hood, Easy to have dry grass and dust clog up filters.

[GotOne]

Hate to sound dumb, but do you soak the air filter in oil and ring it out.......or something like that:) One more thing, it is back firing now when you turn it off. What causes this?

[Surface Tension]

It probably is running hot if the muffler is igniting gas after its shut off. What happens is when you shut down it kills the spark to the plugs. The engine is still spinning and pumping gas to the intake, then its cycled out unburnt into the the exhaust. Normally the muffler isn't cherry red and you won't get a bang. There could be a couple reasons why its running hot.

Restricted cooling air flow: Clean out the leaves and grass around the cooling fins on the head and the shroud. Mice like to nest in that area around the shroud. Also the air intake on top by the recoil/flywheel should be free of debris.

If that all checks out then you have to look at other causes.

Incorrect spark plug, I higher heat range will make an air cooled engine run hotter.

Dirty carb. A dirty carb will run lean and make an engine run hotter.

Dirty fuel filter: If the engine has one replace it.

Weak fuel pump: The engine won't get enough gas and run lean/hot.

Excessive RPMs: Are you needing to run at full throttle to cut the grass? Does the engine bog? Could be the governor isn't working. The engine should keep a constant RPM as the load increases and decreases.

Low on Oil: Change the oil.

Air filter: If your engine calls for an oil soaked filter then thats what you need. This effects how much and how gas is pulled into the engine. No filter would make the engine run lean/hot.

[Nutty Fisherman]

most air filters now days are dry.

[GotOne]

Thanks for the advise. Followed it and also the B/S website and got it running cooler. Mostly common sense, that I apparently lack:).