GT 2554 Problems Running
 

Wondering if anyone would have some insight to a problem I am having with my CC GT 2554. Has a 23hp twin cylinder Kohler engine with about 600 hours.

Last year it started acting up by stalling after about 20 minutes of mowing. Had to leave it cool off before I could get it running again, which would then repeat by stalling after it got hot.

Needed to replace a rusty floor board anyway so I took the tractor down, pulled the tank to clean, ran new fuel lines, replaced fuel filter and plugs. Replaced the coils with OEM Kohler coils so has new coils and wires of course.

Pulled engine to do coils so I could gap coils per spec. Put back together and couldn’t get started. Decided it was a fuel pump issue so I purchased new fuel pump. Got it running but would do the same thing. Run and stall after it got hot.

At times it appeared to be starving for fuel so I originally pulled carb and cleaned but then ended up replacing the carb also thinking that might be the issue.

Still not solved. Runs for 20 minutes and then stalls like its starving for gas. Have even tried putting a vacuum operated fuel pump system on it and that also doesn’t help.

Any thoughts on what might be happening would be amazingly helpful. Thank you

After it stops check for spark, coils when they get warm they quit, early sign of going bad

Clogged air vent hole in gas cap.

Thanks to all for the quick responses. The coils are new OEM so I would not think they would be bad now.

I have removed the gas cap when it starts to sputter out thinking the same thing (that the gas cap breather hole may be clogged) but that didn’t fix the issue either. I have also tried to run it with the gas cap on but loose enough to get air and no luck.

I have put gas directly in the carb and have been able to get it to run. So in an experiment, I mounted a small motorcycle gas tank on the hood and connected the line from the carb to the petcock on the tank. Ran fine for about 30 minutes then started sputtering and quit on me again.

Oh...forgot. I also use a homemade little spark tester as well with a ground wire set up so I could ground a spark plug to the frame and plug a coil on it when it started running poorly to see if spark was the issue but it was not. The spark is strong in both sides when it starts to quit.

If you are squirting fuel in the carb and it runs instead of quitting, then you do have a fuel delivery problem.
But, have you checked valve clearance?
I'm thinking it is an OHV engine
Disclaimer:
I am not familiar with your engine/tractor.:bigthink:

With all you have done the only thing I can think of is the engine may be developing a vacuum leak when it gets hot. Does applying some choke when it starts to sputter help? Can buy a cheap vacuum gauge and monitor the vacuum to see if vacuum starts dropping as the engine heats up.

What "Twin Kohler" does it have?

The Kohler is an OHV and is a CH23S.

The vacuum leak is an interesting thought.

Good thought. The choke is the only way to get it started when it stalls out. I initially thought That is why there could be a fuel delivery issue. However, with the gas tank mounted to the hood and directly feeding the carb, I wouldn’t think that is still the issue.

Any thoughts on where to start looking for a vacuum leak?