Gt 2550 Fuel Issue
 

Good afternoon all. I have been dealing with an issue on my 2005 gt 2550 with a kohler ch23 engine. i bought this machine used last year and have been working out the bugs. The issue i am having is the fuel pump runs out fuel. I have taken off the fuel tank cleaned it drilled out the nipple and all new fuel line. I have the insulation on the fuel line where it comes up to the fuel pump. Replaced the valve cover fuel pump with a genuine kohler pump, and new fuel cap. I can run for about an hour or so and it basically runs out of fuel. I take the line off the fuel pump and it lower it to the ground and gas eventually runs out so no blockage i assume. Once i get fuel back to the pump it will start and run sometimes it stalls again and i have to repeat taking off the line. Any advice would be greatly appreciated as i can not think of what i am missing. Thank you!

There are two nipples.... in the tank and on the pump that is.

Check that the vent in your fuel cap is not clogged.
(you can try mowing with the cap slightly loose to confirm)

I have tried running with the cap loose and it does the same thing.

Are the hoses connected correctly?

Hose are on correct i double checked

Filter on correct, or the correct one?

i had a generic filter on and it was flowing correctly, i switched to a smaller briggs and stratton filter because i read that it had less restriction.

I would think there may be an issue with the carb needle, or float set too high.

Would the float being set to high cause the fuel pump to be empty? when it stalls there is no fuel coming out of the pump until i take off the lower line and get it flowing again

Try hooking the fuel line directly to the carb bypassing the fuel pump and see if it runs for more than an hour.

With the tank being lower than the carb is that possible?

As long as the tank is completely full it will push the gas out. You can check by pulling off the hose and holding it to the height of the carb inlet and see if gas flows into a cup.

I will give it a try

Are the fuel lines correct size and type? They aren't collapsing or being pinched somewhere along the route?

I know you say it runs for an hour then stops "but" is the fuel pump correctly installed the rocker arm that operates the pump will fit in 2 positions but only 1 is the correct one
This is just another opinion , there is a post on here about the correct position

I know this will be a pia but can you put a small tank on the floorboard and run a new suction line to the pump and see if it works any longer?

Is it getting too hot and vapor locking?

Probably not but I know you just put a new Kohler pump on it but with the quality of today's things being built maybe you have a faulty pump. Another thing I might try is switching over to an electric pump or a pulse type pump.

Please keep us posted on what you find.

i had time last night to check a few things. I double checked the routing of the fuel lines all seems fine, and i pulled off the fuel pump to inspect i can operate it by hand and it pumps fuel as far as attaching the line directly to the carb fuel won't run out of the line when its that high I do wonder if the heat is causing issues this motor just seems to run hot

Since you've seemed to have eliminated everything else, I'm placing my vote in the carb float setting category. If the float is causing a lean situation, that might also contribute to it seeming to run hot.

i will check the float level next thank you

If I missed it I apologise, but I see no where that you took the fuel line off the carb, and cranked or run the engine for a quick minute.
it should be squirting fuel with every pulse and a goodly amount, till the carb bowl runs dry and the engine quits ( or you let off the starter if cranking)
I have seen mechanical fuel pumps that had a loose valve in the pump bore and the valve,and or a broken spring just flopped in the worn out plastic housing.
You might have a failing pump.
I'm not one to shotgun parts at a problem but if you are not seeing fuel pulse out of the pump, that could be a problem,
it should pulse like a dog pissing, not an old fart with a prostate problem. :biggrin2:

So what i have found is when the engine stalls i take off the line from the fuel pump to the carb and crank usually a little bit of fuel will spit but not much, the i take off the line from the tank to the fuel pump and hold it down to the ground to get fuel flowing reattach when i have a good flow and crank till i have a steady stream of fuel then hook the line back to the carb and it fires up sometimes long enough for me to finish mowing or sometimes i have to repeat the process again

It almost sounds like there is still trash in the tank.

i have taken it off the machine twice and cleaned it with new fuel and blew it out with compressed air i was hoping to find it full of debris

Sounds like you may have a defective fuel pump. To eliminate that as your problem you can remove the hoses from tank and carb. Place the tank hose end in a container of gas and aim the carb hose end away from anything hot or that creates spark and while holding container of gas below pump crank engine over. If pump pulses a good amount of fuel your pump is probably good and you have issues with either tank or carb. Please be very careful around gas and only perform this test outside and away from buildings.

Is the pump held togther with fastners so it can be taken apart?
If so, take it apart and inspect,I have seen a few that had problems as I mentioned in the previous post.