Kohler Engine: Oil Turning to Napalm.

[chubbs1]

Hello,

Forgive me for my ignorance but I have a older Kohler riding mower (I think it is 15 HP) 4 stroke and the last 4 weeks when I check the oil before cutting it is full of gas. The first time I noticed it I just thought it was some blowby so I started it and it sprayed napalm out of the muffler. I had to jump off and turn the hose on and put out the fire. I changed the oil and it was like pure gas. So every week I have to change the oil (1-1/4qts), luckily I have a lot of 5w30 on hand that I recycle from my cars to mower. Once I change the oil it runs like a top. What could be causing about 1/2 qt of gasoline getting into the engine during downtime?

thanks in advance

 

[Scott88]

A gummed up and/or misfunctioning part in the carb is probably allowing fuel to leak into the cylinder and crankcase.. You could try running a cleaner through the gas, and if that doesn't work, a new or rebuilt carb should.

Try looking up "carb float needle"

A band aid "fix" is to install a cut off valve on the fuel line.

 

[tomcat27]

First of all - that sounds pretty cool !!! (sorry...) Agree that the problem is most likely a gummed up carb, misadjusted float, stuck (open) needle valve. although I don't think that simply running cleaner thru the gas will help.

 

[229]

Replace the needle and seat. Dangerous to operate.

 

[FNFAL308]

Pull the carb and clean it..

The needle and seat are not working correctly or the fuel solenoid is sticking when you turn the mower off allowing gravity feed to fill the crank case. The carb fills up with fuel, then it goes through the intake and into the eng through the valves. It's also possible you have a pc of trash in there not allowing the needle to seat.

The float could also have a pin hole, or small crack in it so it fills with fuel and never allows the needle to seat. This is unlikely but I would check it just the same. When you take the carb apart remove the float and shake it, it's easy to tell if there is fuel in it. The float will not be out of adj unless someone has been in the carb already and messed with it.. Floats don't just get out of adj by themselves and many are not even adjustable anyway.

This needs to be fixed, it's Not good for the engine and as you already found out very unsafe.

 

[JTK]

You might also want to throw a shut-off valve on the fuel line between the tank and carb.

 

[MichiganMadMan]

Originally Posted By: JTK
You might also want to throw a shut-off valve on the fuel line between the tank and carb.

+1

 

[smeltjr]

Chubbs,
I do not know what this on, but my cv15 was also "creating" oil and same issues. The overflow is blowing back through the valve breather and flooding out the carb. The solution, if you have the same motor, is the fuel pump. It is a click pulse unit opposite side of the carb by the starter. It will set you back about $30. If you have no fuel pump.........do the carb stuff. I have been in the exact same boat.

 

[car54]

yeah, my guess is the fuelpump is leaking into the sump. it happens occasionally on these engines. If that much gas was leaking thru the carb and down the intake, chances are the engine would hydrolock and fail to start.

 

[FNFAL308]

Originally Posted By: car54
yeah, my guess is the fuelpump is leaking into the sump. it happens occasionally on these engines. If that much gas was leaking thru the carb and down the intake, chances are the engine would hydrolock and fail to start.


In all the fuel filled crancases I've seen I've never seen it caused by the Fuel Pump??
Can't even tell you how many times I've had the unit come in with an EMPTY fuel tank and a FULL Crancase..
Yup sometimes they do lock up, but sometinmes they will actually turn over and run..