Wood hauler engine smoking

[thombat4]

When I start my tractor lately it sputters and blows black smoke. Any engine savvy folks here have any advice or tips that I can use to diagnose the trouble? After about a minute it clears up and runs fine. It's a Jacobsen 1650 with a Kohler K341 engine if that helps. Thanks guys.

 

[newby79]

Sound like the bowl floats in the carb are not closing all the way. Do the plugs look black and sooty?

 

[thombat4]

Thanks newby79...

I'll check into that when I get home from work today. That's just what I was hoping for...things to look for and check.

 

[projectsho89]

Probably the float needle and/or its seat is leaking gas while it's sitting.

If the float were sticking and not closing, it wouldn't run normally unless someone re-adjusted the mixture to compensate.

Steve

 

[avalancher]

If you are able to eliminate the carb as being the problem, take a look at the head cooling fins closely. Kohler had a few years where they had a tendency to blow head gaskets between the cylinder and the pushrod galley, letting oil seep into the cylinder. The problem you describe is the first symptom of a gasket leaking, quickly followed by oil appearing on and around the head and cylinder.
I had a post on here about this same problem with a Kohler blowing head gaskets, finally got kohler involved at the coporate level even though it was long out of warranty. They sent me two new heads and gasket kits.

 

[thombat4]

Probably the float needle and/or its seat is leaking gas while it's sitting.

If the float were sticking and not closing, it wouldn't run normally unless someone re-adjusted the mixture to compensate.

Steve

Come to think of it I did notice a very small damp spot on the garage floor under the tractor that could very well have been fuel.

 

[Octane]

If its not the carb, it could also be the valve seats.
If the valve seats are worn, it will allow a little oil to drip into the combustion chamber while the engine is sitting, and if the engine sits overnight or for a few days it will drip enough oil to cause it to smoke for about 30 seconds when you first start the engine the next time.
I use to have an old Honda walkbehind mower that would do that. It would spew black smoke for about 30 seconds and then it would clear out. The problem was worn valve seats.
If thats the case, its really nothing to worry about.
Sounds to me like maybe its a Kohler thing. My father and my brother have both owned Craftsman garden tractors with Kohler engines and from day 1 they both would spew black smoke when you first start them up. My father ended up returning his Craftsman tractor and exchanging it for the same identical tractor and the new one had the same problem. Im definetly not a fan of Kohler engines...

 

[thombat4]

If its not the carb, it could also be the valve seats.
If the valve seats are worn, it will allow a little oil to drip into the combustion chamber while the engine is sitting, and if the engine sits overnight or for a few days it will drip enough oil to cause it to smoke for about 30 seconds when you first start the engine the next time.
I use to have an old Honda walkbehind mower that would do that. It would spew black smoke for about 30 seconds and then it would clear out. The problem was worn valve seats.
If thats the case, its really nothing to worry about.

I hope it's something as simple as that...tractor's over 30 years old but has been very reliable.

 

[bigjake]

all i work on are 4 stroke stuff if its black its gas .and its not valve seats its
the valve guids or guid seals that make a engine smoke on start up but thats blue .your carb is leaking fuel when the engine is turned off .and it clears up once burned .if it was a head gasket it would not clear up and would lack power .if you can raise the carb up and put something under it and you will see were the fuel is coming from .Bottom line gas is in the motor when you fire it .unless the choke is sticking.Good Luck

 

[merlynr]

If its not the carb, it could also be the valve seats.
If the valve seats are worn, it will allow a little oil to drip into the combustion chamber while the engine is sitting, and if the engine sits overnight or for a few days it will drip enough oil to cause it to smoke for about 30 seconds when you first start the engine the next time.
I use to have an old Honda walkbehind mower that would do that. It would spew black smoke for about 30 seconds and then it would clear out. The problem was worn valve seats.
If thats the case, its really nothing to worry about.
Sounds to me like maybe its a Kohler thing. My father and my brother have both owned Craftsman garden tractors with Kohler engines and from day 1 they both would spew black smoke when you first start them up. My father ended up returning his Craftsman tractor and exchanging it for the same identical tractor and the new one had the same problem. Im definetly not a fan of Kohler engines...

I'm not too familiar with Kohler engines, but if it isn't ohv engine then it probably isn't valve seats(actually valve seals). Oil smoke is usually kind of bluish. I'd think it's probably float valve in carb. If it's gravity feed gas tank, you can put a cheap(4-5 dollars )in line with gas line and shut it off when not using. I got tired of trying to fix my carb and after putting in shut off valve no more dripping.

 

[ASEMASTER]

it's the carb

If you have black smoke it's from unburned fuel ,the float is high or the needle is sticking, or the choke is on to long. any other engine trouble would give you a gray or white smoke . good luck.

 

[saxman]

Those old "K" series Kohler engines are bullet proof and very durable. Cast iron blocks and roller main bearings. The newer twin series Kohler's had the head gasket problems I believe. I would almost bet that the carb needs a little work to keep the engine from flooding and causing the black smoke.

 

[streeter]

When I start my tractor lately it sputters and blows black smoke. Any engine savvy folks here have any advice or tips that I can use to diagnose the trouble? After about a minute it clears up and runs fine. It's a Jacobsen 1650 with a Kohler K341 engine if that helps. Thanks guys.

Black smoke=Carb problems

 

[Geez]

As previously stated... generally black smoke is unburned fuel, blue or grey smoke is oil and white smoke is usually water or coolant (steam).

 

[J.W Younger]

As previously stated... generally black smoke is unburned fuel, blue or grey smoke is oil and white smoke is usually water or coolant (steam).

the fuel shut off valve is a good idea with any gravity fed fuel sys. an added benifit is you can shut it an run the bowl dry when storing and avoid a lot of problems.

 

[1 woodpile]

first of all start with the easy stuff first... check your gas inside tank see if dirt in it, check your choke is not sticking... then your carb it might just got a little piece of dirt on the needle.

 

[avalancher]

all i work on are 4 stroke stuff if its black its gas .and its not valve seats its
the valve guids or guid seals that make a engine smoke on start up but thats blue .your carb is leaking fuel when the engine is turned off .and it clears up once burned .if it was a head gasket it would not clear up and would lack power .if you can raise the carb up and put something under it and you will see were the fuel is coming from .Bottom line gas is in the motor when you fire it .unless the choke is sticking.Good Luck

Got to disagree with you on this one. When the gasket starts to go between the push rod galley and the cylinder, it will smoke on start up but will quickly go away. The head and cylinder heats up and expands, squeezing the gasket tighter and the leak stops.At least at first. There will be no noticeable power loss. As the leak gets worse, and this can take some time, the smoking will continue even after warm up.
I only mentioned this because I had the same problem as the OP, and this ended up being the problem. Replaced several head gaskets on the Kohler and only after the head was replaced did the problem cease. The head was checked each time for being flat, it was .03 out of flat, the kohler specs called for .04 or greater before the head needed replacing. The last time Kohler sent me two new heads and the problem ceased.
I would only pursue this avenue after fuel was eliminated as the source.
One way to eliminate the gasket problem right off the bat is to pull the plug wire on one cylinder and see if the problem persists. The next cold start pull the other plug wire. If it still smokes during start up, chances are the heads/gasket are okay, small chance that both went bad at the same time.

 

[thombat4]

Engine update...

When I got home yesterday I took the wingnut off the air cleaner and immediately a small amount of gas started pouring out of the cover. There is a fuel shutoff under the tank so for now I'll use it to stop the flow. You carb guys appear to be right on the money. Thanks.

 

[thombat4]

the fuel shut off valve is a good idea with any gravity fed fuel sys. an added benifit is you can shut it an run the bowl dry when storing and avoid a lot of problems.

+1:agree2: :agree2:

 

[bullseye13]

For those who arent familiar with a kohler k341, it is a cast iron kohler, L-head configurartion. No pushrods, no valve seals, ect. It definately sounds like the carb. If it were the head gasket it would just lose power and there would be a noticible leak of gunk around it. Rebuild the carb and adjust the float. "so easy a cave man could do it" comes to mind with those carbs. Adjusting them is nice and easy too. Your local small engine shop should have a kit for 10-14 bucks (get the kit with the new needle and seat +gaskets). Good luck