Kohler Command oil leaking from carb?

[Matt]

Good day y'all, its winter up here where i am and not using the rider but have an interesting situation going on here. The rider is a scotts with a 16hp kohler command single, engine has given me trouble free operation since new, almost 20 years. Regular oil and filter changes and air filters changes and cleaning as required.

I jacked up the rear end as i seem to be loosing air in one of the rear tires, i jacked the unit up from the rear as to place some blocking under the rear axle, no big deal. I went out the other morning to the shop and saw a huge puddle of oil all over the floor, directly under the motor. After the cleanup i started to investigate, the oil on the floor was like new, even though it had seen a summers worth of running the previous summer, and quite a bit was on the floor.

I checked the oil level via the dipstick and indeed it was quite low but did register on the very bottom of the dipstick. I took the air filter off and had a look around and gain more visibility in that area, i can see down the lower filter housing that leads into the throat of the carb that there is oil in there and the whole area is wet with oil. Question i have, how did so much oil get to the carb?? Can oil leak out the vent tube and run into the carb and filter housing, i can see the valve cover and what i believe vent tube, is this where the likely leak is coming from? I have jacked up the the rear of this machine many times and never had this happen before, what might be happening here??

Thanks for any/all advice, peace.

[RoyM]

When you jacked it up the carburetor was on the low side, oil entered via the crankcase breather hose. Clean everything up and replace the air filter which is likely saturated.

[Matt]

Thanks RoyM, oddly enough, the air filter came out unscathed, not a drop of oil on it, yah, ill clean everything up and re-fill the crankcase, thanks!

[38racing]

Is the fuel line to carb shut?. Could it be oil ran out with gas and the gas has evaporated away?

[Matt]

Is the fuel line to carb shut?. Could it be oil ran out with gas and the gas has evaporated away?

The fuel tank is full and no evidence of any fuel loss, it had to have dumped out the vent as RoyM stated and i suspected. Oddly enough, the fuel line has no shutoff/petcock, i installed an inline one to able to shut the fuel off and the plastic fuel valve actually melted!!! It was one of the most bizarre things i have seen, it was a laser brand straight fuel shutoff valve, after 6 months, it actually melted. Has to be the ethanol fuel which i try to avoid but when buying regular grade, all of it around here has ethanol blended.

Thanks! Peace

[KE4AVB]

For a 20yr engine CV16 I won't be surprised that oil in the carb is from blow by or a worn breather reed valve. Oil doesn't flow uphill by itself.

With doing it when just sitting there and the oil level is very low I would think it is the crankshaft PTO seal that is bad. I have seen several bad oil seals where they have corroded around the outside retaining surface. I even seen one Briggs crankcase cover (oil pan) cracked. If you're unable to find the leak use an UV dye tracer for gas/oil. It is about 8 usd for 2 oz shot which you can use 1 oz at a time on these small engines. The area will be the brightest at the leak source when UV (blacklight) light is shined on it. Here I use a 15W CFL bulb I got from Tram-law. A small flashlight version would work better as can get it around the equipment easier but I just haven't look for one lately. I had one that I used with UV marker when marking used parts but the battery is dead and is non-replaceable.

[38racing]

i have a thread somewhere where a Tecumseh vtwin dumped oil out the seal when crankcase flooded and continued after to leak. turned out to have major lower cover bearing where. found same wear in two same engines.

[Matt]

After leveling the machine, everything seems to be fine, this major dump happened when i lifted the rear of the machine to block the rear up to take pressure off the leaking tire. When the temps get better and re-install the battery, ill know more then, thanks for the heads up.

Matt