Outdoor Power Equipment and Small Engines - Smokes a lot

My lawn tractor engine began smoking heavily, missing and loosing power. "Kohler 25 hsp (twin cyl)

It appears that one plug is fouling or at least has a lot more buildup than the other one.

That is bad enough, but my 14.5 hsp briggs/straton in another mower began doing the same thing (had been towing a small utility cart)

Both began using a lot of oil previous to the heavy smoke with diminished power. Both still run, but they both get lost in the fumes and smoke after a while.

It the fix something I can do myself with some tools?

Thanks

A blown head gasket could be to blame for both of your engines.
Fish

Hello hopro, I would do a compression check on both of these engines. If you have an Auto Zone near you you can do a loan for a tester. Screw it into the spark plug hole and run the engine through a few times. On the twin remove both plugs for the test. If you have less than 75 lbs. that is probably the problem.....Mike

Hello hopro!

It could be the things mentioned in the previous replies. It could also be that the engine is over-filled with oil. Also, the oil could be thinned by gas if the carb needle valve isn't sealing. Check for gassy-smelling oil. There could be a PCV problem on the Briggs. I don't think it's a PCV problem on the Kohler though.

Did these engines begin smoking gradually...as in months or years? Or all of a sudden?

Much appreciation for the wonderful replies.

Cheese,

Both have been smoking more than they should, but they suddenly started, while being used, smoking too much and substantial loss of power.

Thanks

Did you check the things we mentioned? Check these things and you'll likely find the problem. You may be in need of rings too, but the other stuff is so easy to check. Do that first.

It would also be helpfull to know the color of the smoke , for instance a blueish smoke would indicate that it's burning oil , a more blackish color tends to fuel richness . After you do the other checks , get a new air filter , a clogged or dirty air filter will cause the blackish smoke and loss of power . If all the checks don't solve the problem , then I would look at the exhaust valve and port , this can also cause smoke and loss of power .

You havn't tipped the machine at all and filled the air filter or manifolds with oil. Don't laugh I have seen it loads