kohler courage 20

kingman13185

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I have a troy bilt with a kohler courage 20 sv 601. I'm having a fuel issue. I start the tractor and it runs just fine for a few minutes and then it stops. At that point I look and it stops pumping gas and the filter is empty. If I pull the hose off the filter, the fuel comes out and then I start it and it runs good again. I replaced the carb and still same issue. Any help???
 

StarTech

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Need equipment info but if it is a gravity flow system it maybe vapor locking. I had a customer the fuel was boiling in the fuel line due excess heat from the muffler. Had to insulate the fuel lines.
 

kingman13185

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Need equipment info but if it is a gravity flow system it maybe vapor locking. I had a customer the fuel was boiling in the fuel line due excess heat from the muffler. Had to insulate the fuel lines.
It is gravity flow. Its a SV 601. What does vapor locking mean? what can I do?
 

bertsmobile1

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IT could also be the fuel pump check valve failing
Having said that I have only ever replaced 2 faulty fuel pumps in 11 years but it does happen on occasions
The fuel pump has 1 or 2 check valves in it so fuel can only go from the inlet to the outlet
Try blowing backwards through it
If you can then either the check valve is faulty or the diaphragm has a puncture .
With a vapour lock you get what is basically an air bubble in the fuel line and air compresses easily so the pump compresses the air bubble rather than pushing the fuel into the carb .
Bad fuel can soften the Vitton tip on some carb needles or soften the rubber seat on Walbro carbs so the needle sticks to the seat when it gets hot thus no fuel flow .

BEcause you multi posted I can not remember if on your other thread you said you replaced the carb & fuel pump . it gets very confusing when people multi post

In any case these engines have a very large crankcase volume, so the pressure pulses that power the pump are some what weak
Thus the tube that connects the fuel pump to the engine must be in good condition
These engines also had a problem with the front 4 crank case bolts backing off but as you engine is rated 20 Hp the bolt problem should not affect your engine but it will not hurt to remove the blower housing and check they are tight because if they back out you loose crank case pressure pulses .
 

kingman13185

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This tractor is gravity fed and no fuel pump which makes me wonder why it stops getting fuel.
 

StarTech

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So now I am confused
Well it is the operator saying a Gravity fed is pumping fuel which it don't that is probably confusing you.

If the operator's is using winter fuel in the US it can start to boil in the fuel lines causing fuel vapor which more volume to pump the fuel back up the fuel line. Hence vapor locking the system. Fuel can boil in temperature as low 140F. Kohler Courage actually had a problem with this so Kohler came out with a kit to shield the carb fuel bowl and fuel solenoid. I seen this problem only a few times here and even had to insulate the fuel lines themselves. This problem is not unifque to Kohler Courage either as I have JD mowers with factory heat shielding of the fuel lines. I even had one MTD rider that also had the same problem. This mainly cause by the heat being blown back from the muffler. I actually measured a temp of over 400 F on one mower that was vapor locking around the fuel line.
 
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