F2560 sputters

[Cottonwood]

I have a F2560 front mount mower with a 72 deck. Have had it for 16 years. This summer it started to lose power briefly once the fuel was at half and under. This only happens when going downhill, and generally while turning left. It gets worse as the fuel gets lower, but never stalls out, just sputters like its running short of fuel. Its like the machine picks up air, and then when you level out, away it goes.

If it was a safety switch the fuel level should not seem to impact it. If it was a filter then it should do it anytime, any fuel level. Would seem the same for the pump, or for something in the tank. The fuel pickup tube comes to mind, but the part I can reach is solid and doesn’t appear to have moved. I can’t see into the tank to the bottom and wondered it there is another part to the tube that could have fallen off, or come lose and the tube picks up air. The consistency of this issue is baffling.

Since the part of the tube be I can feel seems pretty solid, it does not seem possible it has a pin hole wore into it? Anyone have any idea, or even a schematic showing the path of the fuel tube in the tank?

Thanks.

 

[Dave_eng]

Your symptoms all fit a failed fuel lift pump when you keep in mind your F2560 is like a tractor in reverse.

A regular tractor with a failed lift pump has problems going up a hill whereas you have problems going down a hill.

Before replacing the pump check for power to the existing pump which should be present any time key is ON

Recently I posted a more complete explanation on lift pumps for the owner of a regular tractor:

Your one comment catches my attention: After an hour of use and nose uphill.

Often the tractor's design allows fuel to flow from the tank to the injection pump by gravity alone.

A pump is added to deal with lower than full tank levels and in addition to situations where the tank is lower than the engine such as going up hill.

The reason the pump is called a "LIFT" pump is because it lifts the fuel up to replicate gravity.

Check the fuse feeding the fuel pump. Check for power at the fuel pump when the key is ON. Check for steady fuel discharge from the pump or filter by opening the line.

Replace pump if fuel delivery is suspect.

When the tractor starts acting up turn around and back up the hill. You will find it runs better if the cause is as i suspect.

Dave

 

[JD55]

I had a loose clamp on the fuel filter that periodically allowed air into the fuel line replaced the clamps and everything is good.
check and see that the fuel filter is full of fuel.

 

[Cottonwood]

Your symptoms all fit a failed fuel lift pump when you keep in mind your F2560 is like a tractor in reverse.

A regular tractor with a failed lift pump has problems going up a hill whereas you have problems going down a hill.

View attachment 47637

Before replacing the pump check for power to the existing pump which should be present any time key is ON

Recently I posted a more complete explanation on lift pumps for the owner of a regular tractor:

Your one comment catches my attention: After an hour of use and nose uphill.

Often the tractor's design allows fuel to flow from the tank to the injection pump by gravity alone.

A pump is added to deal with lower than full tank levels and in addition to situations where the tank is lower than the engine such as going up hill.

The reason the pump is called a "LIFT" pump is because it lifts the fuel up to replicate gravity.

Check the fuse feeding the fuel pump. Check for power at the fuel pump when the key is ON. Check for steady fuel discharge from the pump or filter by opening the line.

Replace pump if fuel delivery is suspect.

When the tractor starts acting up turn around and back up the hill. You will find it runs better if the cause is as i suspect.

Dave

 

[Cottonwood]

Your symptoms all fit a failed fuel lift pump when you keep in mind your F2560 is like a tractor in reverse.

A regular tractor with a failed lift pump has problems going up a hill whereas you have problems going down a hill.

View attachment 47637

Before replacing the pump check for power to the existing pump which should be present any time key is ON

Recently I posted a more complete explanation on lift pumps for the owner of a regular tractor:

Your one comment catches my attention: After an hour of use and nose uphill.

Often the tractor's design allows fuel to flow from the tank to the injection pump by gravity alone.

A pump is added to deal with lower than full tank levels and in addition to situations where the tank is lower than the engine such as going up hill.

The reason the pump is called a "LIFT" pump is because it lifts the fuel up to replicate gravity.

Check the fuse feeding the fuel pump. Check for power at the fuel pump when the key is ON. Check for steady fuel discharge from the pump or filter by opening the line.

Replace pump if fuel delivery is suspect.

When the tractor starts acting up turn around and back up the hill. You will find it runs better if the cause is as i suspect.

Dave

Thanks.
I had contemplated the fact that going downhill half full of fuel causes a weak pump to underperform. And yes when I get turned uphill it cures itself. And as the tank gets lower, the problem escalates. I imagine I will start with a pump replacement.

 

[Cottonwood]

Thanks, the other day I stuck a new fuel pump and filters on it. Tank was around a quarter full and it mowed up and down hills nicely. I also think it runs a little smoother, but that could just be me? The new pump is bigger than the old one also. plus this one I can hear when i turn the key on, very audible, the other one I could not unless I went next to it. Thanks again.