Riding lawn mower problem

My first thought is that you probably don't actually have a fuel pump. Riding mowers typically have gravity fuel feed. If it did have a pump, it is unlikely that you could still drive the mower on any slope steep enough to affect fuel delivery -- however, this can happen with gravity fuel feed if the slope is steep enough, and a clogged fuel filter will make it worse. Have you tried changing it?

My second thought is that the slope may be steep enough that the hose from the fuel tank to the carburetor is above the level of the fuel (and thus you're getting air in the fuel line). This can occur either with pumped or gravity fuel feed. It's also much less likely to happen if the tank is full -- had you noticed whether that makes any difference?

If the slope *is* that steep, you probably should reconsider your mowing pattern.

Clean the fuel cap vent, or loosen the cap a tiny bit.

-- Oren

"If things get any worse, I'll have to ask you to stop helping me."

If your carb has a float, it could be leaky. A little gas in the float might make it heavy enough to starve the engine of gas when the engine is sloped the right (wrong) way with respect to the float hinge.

I've always thought it was safer to mow a slope up and down unless it's a very gentle slope....

HTH,

Paul F.

If your tractor has a Kohler twin engine you do have a pulse fuel pump. Make ABSOLUTELY sure you replaced the fuel filter with the correct Kohler OEM part. There have been numerous posts and reports about problems after a fuel filter change when NOT using the correct Kohler fuel filter. fuel filters may look similar but thwey have different filtering characteristics and flow rates.

You can check here for the right one...

I had this problem when water had gotten into the fuel tank on my Honda. The Honda's tank has a slight depression located away from the fuel pick-up. The depression is there to collect water and other crap that gets into the tank.

However, once the depression was full of water, the water would spill out of the depression when the mower was on steep slopes, and get into the fuel line feeding the carb.

KB

That makes sense. I went out and cleaned it out. How did you come up with that?

a heavy float will cause the needle valve to dump more fuel in the bowl

I used to have to cut a sloped front yard and my 18HP tractor would act up. Once I cleared the cap vent - she ran fine.

It is also a "troubleshooting tip" for small engines with fuel problems. Good practice to start with the easy stuff, first :)

So did clearing the cap vent work. You didn't mention it.

-- Oren

"If things get any worse, I'll have to ask you to stop helping me."

Probably have to wait until the next time he mows :)

Not familiar with the engine. Does it have a low oil pressure cut off?

-- Oren

"I didn?t say it was your fault, I said I was blaming you."

I am sorry. I don't know and don't know how to find out.