I have 30hrs. on my 20hp Kohler 7000 series engine, valve cover was leaking badly on right side and looks like a burnt valve. Any help would be appreciated.
That is not a burnt valve
It is oil burning on the surface
The oil is being forced up the valve stem usually because the crankcase pressure is too high.
High crankcase pressure is generally due to either a blown head gasket or a faulty breather.
Overheating around the exhaust port is usually caused from to little valve lash so the exhaust valve opens too early & closes too late.
#3
cpurvis
Does the other exhaust valve look like this?
#4
StarTech
Could also be cause by other problem such as restrictive exhaust or burning too lean fuel mixture wise causing excessive exhaust temps.
If this engine is still under warranty (30 hours), I'd let the dealer take a look at it.
If not, I'd remove that head and look at it myself.
#7
Mower King
Like others have said, that is not a burnt valve. That is oil burning on the head because, that is the Exhaust valve and that is where all the heat is centered. This is a result of too much heat, causes can be many....debris build-up on the cooling fins of that cyl head, debris build-up on grass screen (air intake on top of eng for cooling), engine not being run a WOT or eng not turning enough rpm's...among other things, but, you have cleaned up the sealant area for the V cover to seal real good!
The only way to "SEE" a burnt valve is to remove a head and look at the valve were it mates the V seat!
#8
cpurvis
The other symptom that seems to be overlooked is the fact that the valve cover was leaking oil "badly." That indicates (to me) that exhaust gas leaking past the valve stem is the problem.
I might have found the problem, noticed the exhaust was loose after closer inspection only one bolt holding it on (loose) and no gasket. Thank you sears. Only question now is how much damage did it do?
