Not drawing fuel ?

[Sheridan1]

I have a 17 HP Kohler engine on an older Sears Craftsman mower. I was have an issue with the engine running and drawing the fuel filter dry and then not taking fuel like a stuck float. I checked and cleaned the carb and eventually replaced the carb. Now, it still does the same thing, i've replaced the fuel line with new filter and an in line shut off since I saw that one fix could possibly be the little plunger which is on the bottom of the bowl. The "fix" was to cut it off which still did not fix the problem. Fuel flow is good right up to the carb intake. When removed the carb is clear and the float operates properly.

Any ideas on what's causing this?

 

[Rivets]

Have you checked for debris in the fuel tank? Another thing to check the next time it happens disconnect the fuel line from the filter and see if the fuel starts following again. When you post back please include model and serial numbers for both the unit and engine. The techs here are not psychic, like many of the DIY guys here, and really really hate making guesses as to the problem.

 

[Sheridan1]

Thank You for your reply. I checked the fuel tank and fuel line from the tank to the carb before installation of the new carb, there was no debris in the tank or line and fuel flows freely when disconnected as you have suggested. I've even checked that the gas cap is venting properly and tried running the unit with the cap slightly loostened. The model number for the lawn tractor is 917.272075, the engine is model number CV490S.

 

[Hammermechanicman]

Does engine have a fuel pump or gravity fed system?
You say "drawing the fuel filter dry". Have you tried just removing the filter and see how it runs?

 

[Born2Mow]

HMM is correct. Nothing in the carb "draws" fuel in. It is either delivered by gravity, that is the tank is above the carb. OR, if the tank is below the carb, then there is a pump that is usually operated by vacuum pulses from the engine.

I bet your vacuum hose has a leak, or the flapper inside the pump has developed a leak.

 

[Sheridan1]

This is definately a gravity system. Fuel flows freely when the line is disconnected from the carb, fuel also flows when I remove the bowl on the carb and stops when I raise the float manually.

 

[slomo]

Sounds like you covered the fuel issue. If you remove the carb bowl, fuel should drain out of the carb body. Should be running down your hand and making a mess.

Might check the carb needle and seat. Flip the carb over. Needle should hold like 7PSI and not leak down. Let it sit with pressure on it for a while, should hold.

No chance on having the shut off in the closed or cracked partially open position? Just asking. You already covered the cap loosening trick.

slomo

 

[tagpop]

Things I have found in gas tanks the second or third time I cleaned them out: paper from the cap, a small tree leaf (took 3 cleanings to find that leaf) and just recently I found a baby lizard partially blocking the line. These were all cases where normal checking did not indicate I had any tank or line blockage.

 

[Born2Mow]

Things I have found in gas tanks the second or third time I cleaned them out: paper from the cap, a small tree leaf (took 3 cleanings to find that leaf) and just recently I found a baby lizard partially blocking the line. These were all cases where normal checking did not indicate I had any tank or line blockage.

That lizard most definitely voided the warranty.

The owner's manual explicitly warns against DAMIT. (Drowned Amphibian Malfunction Inside the Tank)
And studies show that, based on what owners are yelling, DAMIT is blamed for more mower breakdowns than any other cause.