Kohler Magnum 20HP problems

[djcgrand 0]

Hi all: Lately I've been getting some oil residue in my air filter housing. Additionally, the plugs have been fouling up pretty quickly and I lose power when under a heavy load. At first I thought it was maybe a dirty air filter and that the engine was sucking air through the breather tube and pulling the oil up with it. However, I removed the air filter cover and ran the engine without the air filter and I can see the residue blowing up through the breather tube. Is this a sign that new rings may be needed? Any thoughts?

[quantico 2]

Sounds like my magnum engine... but maybe 100 hours less oil blowing than mine is..... I am pondering re-power vs rebuild ... both are very expensive options... just can look up the m18 kohler magnum thread... If you decide to replace... let me know , I am looking for a better engine than mine... and yours sounds like it has issues, but is way ahead of where I am... scott

[andrewk 0]

There are a few things you should do first. Oil at the breather is a sign that the engine is not creating a vacuum, but is creating pressure, and pushing oil out the path of least resistance. A crankcase vacuum check is the first thing I would do if it does blow oil out the breather when the air cleaner is removed. The second test would be a compression/leak down test, and that would tell you the condition of the valves and rings. I think somewhere on here is a tutorial on how to make a monometer to check the crankcase vac/pressure. More than likely it is a vac leak from a seal, or a bad breather, but it could be a sign of a worn engine. Hope this helps- Andy