G1800 bogging down while mowing

[Bob01]

After mowing for a while my engine will suddenly bog down and die. After restarting it I can mow for a little while and it will die again. Sometimes just before it dies I can turn off the pto and the engine will smooth out and run again. Could this be the seat switch or is this condition pto related?

 

[zzvyb6]

Doesn't it look like a fuel filter plugged problem? When you need power you need fuel RATE. The filter or pump is limiting your fuel flow rate.

 

[jinman]

Your G1800 has two fuel filters and a fuel pump lift pump. One filter is before the pump and one is on the engine. I think folks often change the engine filter and miss the one that is behind the left rear wheel before the fuel pump. I'd change both these filters and see if the problem goes away. If not, be ready to replace the fuel pump. That's a common failure too on these older mowers. The fuel pump can be tested by removing the outlet hose and turning on the keyswitch. The pump should run and pump out diesel fuel, but the pressure is very low. If it runs and pumps, it is probably okay.

 

[Bob01]

I'm just on my second tank of diesel since the Kubota dealer serviced my fuel system. They supposedly they changed out both my fuel filters and installed a new fuel pump. The bogging down was the reason I took it to be serviced, now it has started doing it again. Today I was mowing and every once and a while when I could feel the bogging start I would disengage the pto lever and increase the speed to keep it running. It's puzzling.

 

[jinman]

I understand your frustration now. I have to believe that either air or water is getting into your system. It also could be the kill solenoid acting up. I don't mean the actual solenoid, but rather the linkage. Do you have the backup kill knob to pull? Make sure that is pushed all the way in. My kill solenoid has been removed and I only use the knob. If the linkage binds, it could be just enough out of position to cause the fuel delivery to be partially cut off. Just brainstorming here. . . .

 

[leonz]

After mowing for a while my engine will suddenly bog down and die. After restarting it I can mow for a little while and it will die again. Sometimes just before it dies I can turn off the pto and the engine will smooth out and run again. Could this be the seat switch or is this condition pto related?

The inlet screen is a likely culprit most of the time.
The injection pump creates a huge pressure gradient
which pulls the fuel in and when you stop and turn off the PTO
The fule is bouncing around and the pump works much less hard when the material is pulled off the screen by the fuel sloshing around.

 

[GPintheMitten]

Sounds like fuel filter / supply or air filter. I just replaced both because my B6200 was bogging down and it runs like a top now.

 

[Transit]

If there is a filter located in the fuel tank I would remove it and look carefully to see if the filter is clogged by diesel bugs. A filter in the tank is hard to service. Also, are the fuel lines in good shape, sometimes the inner lining collapse and blocks off the flow?

 

[Bob01]

Do you have to remove the tank to drain the fuel or can you disconnect the fuel line from the rear fuel filter and drain the tank? Or do you have to remove the body to remove the tank?

 

[leonz]

Do you have to remove the tank to drain the fuel or can you disconnect the fuel line from the rear fuel filter and drain the tank? Or do you have to remove the body to remove the tank?

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The best thing to do is empty the tank by draining it-disconnect the fuel lines
fuel line and the overflow return line and let it drain into a clean diesel can. then you can safely remove it from the tractor and disconnect the base fitting to clean the tank with a little isopropyl alcohol by pouring it into the tank, and shake the tank with the cap on pour out the alcohol let it dry then stick a vacuum wand in it to suck up any dried up junk if it does not fall out.

A second fool proof method is water and a hand full of pea gravel or alcohol and the pea gravel, I would rather see alcohol used as it will evaporate completely.