[joetiii]

I've got an 76 vintage Kohler 12 HP that has served me well through the years. In winter, I have a snowthrower attached to my AC 112 and the engine runs a4/4 to 7/8 throttle while working. I first noticed that the tractor has been using larger amounts of gas this season and I noticed some fresh oil dripping out the carbuerator. I wonder now what this could be?

Engine runs fine and pulls well. a little bit of smoke while running as I do tend to have to add 1/2 quart every couple of months during mowing season.

In the past, I was spraying a little trans fluid through the carb to clean up the valves a bit. I had a mechanic friend suggest this when I was having a stalling problem under full load with the garden tiller attached. Seemed to keep the valves from sticking but I wonder now if that might have something to do with it.

Anyway, back to the question, do you think the oil rings are causing the problem with oil coming back through the carb? or is it an intake valve not sealing properly? Maybe just a overly rich carb adjustment? (gotta be hopeful right?)

 

[Grand Sierra]

Does it have any oil leaks around head gasket? Could be valves, maybe worn rings It's an old engine, maybe a leak down test!

 

[RedOctobyr]

Apologies if this is way off base. But on some Briggs engines, I seem to recall reading that a problem with the crankcase breather (?) can result in oil coming up into the intake. Might be an area to consider? Sorry if I have this wrong.

 

[dodge trucker]

Apologies if this is way off base. But on some Briggs engines, I seem to recall reading that a problem with the crankcase breather (?) can result in oil coming up into the intake. Might be an area to consider? Sorry if I have this wrong.

they all (Tecumseh and Honduh too) have this as a possibility; besides checking this I think I'd pull the head and see how carboned up it and the top of the piston is; this will up the compression ratio and make the crank and piston have to work harder to do their jobs; putting more strain on otherwise "iffy" rings and such....
1/2 a quart a couple times a mowing season dont seem taht bad on oil consumption; but if the valve at one time seized to the stem and the stem and guideare both moving that can certainly create an oil eater; I had that on both a 12HP Kohler and (2) same HP Briggs vertial I/Cs your local auto machine shop can fix; on the Briggs' they found me a oversize (outside diam of guide) and reamed teh block for it, pressed it in it was not a very high cost repair; but it worked.

I have seen these guys do valve jobs on the old kohlers while still in the tractor IF you bring the tractor in when they can "get right to it" so it isnt taking up all that space and with the head carb and breather already removed and depending on the engine in question the muffler and pipe if it would be in the way....

 

[joetiii]

OK, this is all good info. where can i get my hands on a kohler 12HP engine manual so I can check out specs, torques values for when I take off head, check out crankcase breather, etc.? :thThumbsU

 

[joetiii]

Does it have any oil leaks around head gasket? Could be valves, maybe worn rings It's an old engine, maybe a leak down test!

Nope... Its all dry around the head. though I should go and check alittle more carefully as my eyes arent as good as they used to be.

 

[Deereman112]

Before you do anything major, I would suggest you replace the air filter if there is one. I had a briggs motor once with a plugged air filter and it would run fine until it would sucks oil up into the carb. If you were snowblowing with the tractor its possible some of the fine "snow mist" could of built up and plugged the air filter. Its the easiest and most inexpensive thing to do first. If that doesn't fix it I would start looking into breathers etc.

 

[attorney_barnabas_collins]

Kohler manuals are free online, though I don't have a link handy. I 3rd the breather clogged suggestion. Might double check the oil level on level surface too.