What is the model and spec number on the engine? A few of my customers have CV12.5 and CV14's on their Craftsmans. I'll gladly look up the parts diagram and give you some more suggestions if your new filter doesn't work out.

 

Well, it wasn't the vent in the gas cap as the problem continued today and persisted even with the cap off. It ran good until the level in the tank got below the height of the filter. I could see the gas filter was going dry and would slowly refill. If I took the gas line off (did this after the filter) and held it into a jar, I was able to quickly drain out a quart of gas so I don't think the filter is obstructing the flow.

I looked at the carb and it has an electrical connection at the bottom of the bowl but I don't see a fuel pump unless this is it.

The engine is a Kohler Command 16 HP OVH. I can't find an engine model number so once I dig out the book on it, I'll post that on here.

Any new ideas based on this information?

Thanks again.

 

Ray -

If it runs as long as the fuel can get to the carb by gravity, then dies, it definitely sounds like the fuel pump...

The electrical connection on the carb is a fuel shutoff solenoid. But somewhere between the carb and the tank there should be a vacuum operated fuel pump - uses crankcase vacuum to run the pump...

 

Ethanol is turning out to be a small engines worst night mare....How are the jets on the carb?

 

The CV16 should have been designed with Ethanol in mind I think.

I just pulled up the manual on the CV16, but the fuel pump is optional. If it does have one, it would be a camsahft driven unit on the opposite side of the engine where the carb is.

If it does have a fuel pump, it will be right behind the dipstick, as the picture shows

 

OK, I stand corrected on the fuel pump (if there is one) - mechanical, not vacuum...

Let me ask this. Is the level of fuel in the tank above or below the carb when it dies? You said it's at the level of the fuel filter, but what about the carb? Does the fuel line routing have it rise above the level of the carb? Definitely sounds like a fuel delivery problem to the carb...

 

I have that same engine in my Yardman tractor and the carb got messed up because of ethanol

The older engines get hit even harder

 

Thanks for the photo of the engine, Lead Head. Mine looked that nice once upon a time.

I was really starting to doubt myself about the fuel pumo so I just went out there and looked at the mower. As I suspected, no fuel pump and I guess now I know what that blank hole with the two threaded holes in the casting is for....I always wondered what might go there.

I have absolutely no fear that this is ethanol related, Sean. This mower runs perfectly except when it gets fuel starved and stalls. I only run fresh gas in my equipment and always use Stabil for the winter.

As for the fuel line routing, the line comes out of the bottom of the tank, dips down and back up (looks like a sink trap) and then goes to the filter and then straight to the carb. The filter is clipped to the side of the engine at about the level of the bottom of the tank.

I think my next step is to replace all the gas lines and put a new filter in there again. See what happens. Although, this may wait to spring now that the weather is changing for the colder. Time to start worrying about getting the snow blower running.

Thanks for the help so far, gents. Still accepting suggestions....

Ray

 

Have you replaced all of the fuel line Ray?

 

Is there a fuel shut off solenoid? I think KAWI engines have it not positive about Kohler motors.

 

Are you saying there is a hole in the block with two threaded holes? There should be a cover bolted over it.

 

Not a open hole but in the block casting is an indentation where the hole would go. It is about 1" diameter and 1" deep. On each side of the "hole" are two bolt holes that I assume is where the fuel pump would bolt up. Looks a lot like the openings car engines used to have for mechanical fuel pumps.

I wonder if there is an eccentric on the cam and I could retro the mechanical fuel pump if I knocked out the hole in the block? I suppose I could always just bolt a cover over the hole if the cam isn't set up....

 

As you know there is no fuel pump as your fuel tank is right behind the motor and is gravity feed am I correct? The solenoid on the bottom of the carb is a anti backfire solenoid. I would remove the bowl from the bottom of your carb and check for dirt and or a little water in it (this junk gas they are selling us absorbs water) and while you have it apart check and see if the point on the end of the anti backfire solenoid moves in and out freely.The only real problems I have seen with this motor are early ignition coil failure and if the oil is not maintained the hydrolic lifters will pump up and not bleed down and cause valve clearance problems and compression would be low.

 

On my old Kohler K341 the fuel pump was driven off the one of the cam lobes, but not sure how it is on the newer engines. But if it is the same setup, you should be able to just punch out the hole and pickup a fuel pump from kohler.

 

If your fuel filter appears to be partially drained (or at least much less "full") when the issue occurs, it can only mean that you have blockage in the line between the filter and the tank. Next time it starts running rough, pull the fuel line from the carburetor and check flow into a can just to confirm. Fuel should flow from the line in a steady stream that is the same diameter as that of the internal diameter of the fuel line (1/4").
If you confirm that the flow is not adequate at this point, you have to start working backwards from the fuel filter. I have had customers that have had debris lodged in the fuel line shut off. Remove it and flush it out. I can't remember if they can be diasssembled, but if so, do so. I remember only flushing them out. I also remember that it blocked up again because the customer had gotten clippings in the fuel tank (I have no idea how!).
If your description is accurate (that the fuel filter appears full after sitting then mostly drained at the time of starvation issues) then the ONLY possible problem is a blockage in the line somewhere between the tank and the filter. Look in the tank with a flash light to make sure nothin fell in there either.
Fuel starvation issues in the carburetor would not cause the filter to appear to be emptied. The filter is emptying because fuel is being drawn out of it faster than it can refill it. Your symptoms are consistent with this scenario as it usually takes a fair amount of time for the flow inequality to cause the engine performance to suffer. Meaning that although you are operating at a "negative" balance of flow into and out of the filter, the flow is sufficient that the cumulative effect takes awhile to show up.
Consider a leaky bathtub drain. If no water is flowing into the tub, eventually, the tub will be dry. If water enters the tub at the same rate it is leaking out, the level never changes. If water is running into the tub faster than it is leaking out, the tub eventually overflows.

If you want to check the fuel shutoff solenoid even though this is not the problem this time, know that they can fail or work intermittently. They are electromagnets and, as such, have wire windings in them. Much like a faulty coil can operate intermittently once it gets hot due to expansion of the wires breaking the circuit, so concievably could your shut-off solenoid.
It is very easy to test solenoids when the engine is cold by simply listening very carefully when you turn your ignition key to the "run" (NOT "start") position. You should hear a very firm, single "click" from the region of the carb as you engage and disengage the solenoid by turning the key back and forth from the "off" to the "run" position.
A more thorough test can be done by shutting off the fuel, disconnecting the single wire to the solenoid, unscrewing and thus removing the solenoid, reattaching the single wire to the solenoid, and holding the silver exterior of solenoid against a good ground connection. Do be cautious to wipe up any dripped fuel because the ground connection may spark if it is not secure when you turn the key to the "run" position. Sparks + gasoline vapor = BAD.
But, you don't need to check your solenoid this time because that is not where your problem is. If you had a fuel restriction as a result of the solenoid malfunctioning or dirt floating around in the bowl and clogging the jet, your fuel filter would remain full of fuel as the amount entering the filter would be greater than that leaving it.

Kinda long winded, but bottom line: Being that this is a gravity fed fuel system, you have a restriction somewhere between the filter and the tank. Be sure to check the tank, the tank drain opening, the fuel line, and the fuel shut off valve. This is where you will find your problem.

Let us know how you make out.

Oh- and getting the snowblower started? Start by taking the bowl off the carb, wiping it out with a clean paper towel and and letting fuel run freely through the line and needle valve to flush out any condensation that has collected since last winter. 95% of snowblower no-starts (in my experience) are fuel-related and most often water in fuel issues.