Think it's an air problem. Ran the tractor very low on fuel (not out). After fueling rpm's fall off under load. Changed primary and sight glass filters. Not sure I properly bled off air. How much travel is there on the hand pump stroke, located on top of the primary fuel filter ? I'm only able to feel a 1/4 in or less of travel when trying to depress the manual pump.
M6800 Utility Tractor
- Thread starter Team roper
- Start date
Daren Todd
Well-known member
Lifetime Member
Equipment
Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
If your only getting a 1/4 stroke on the fuel pump, it could be a couple things. First is the pump could already be partially in gauged on the engine side of the pump. Theres a tab on a mechanical fuel pump that gets pushed to engage the fuel pump similar to the primer lever or button that we operate with our finger. Bump the engine over slightly and see if it clears up. Try that a couple times. Sometimes it takes more them one bump of the engine to get the right spot.
If that doesn't clear it up, then there could be a partial blockage in the fuel line. Either at a pickup tube, or in one of the fittings up to the fuel pump.
Or simply air locked depending on how the priming system works.
When operating the fuel pump, do you have the bleeder vent open on the injection pump?
If that doesn't clear it up, then there could be a partial blockage in the fuel line. Either at a pickup tube, or in one of the fittings up to the fuel pump.
Or simply air locked depending on how the priming system works.
When operating the fuel pump, do you have the bleeder vent open on the injection pump?
Easiest way to bleed the air is loosen the bolt where the fuel line hooks to the injector pump. Then pump your primer on top of the primary filter. It only moves about 1/4 inch like you described but after a few pumps which seems like it takes forever the fuel will squirt out of the line at the pump. When it does tighten the line down and start it up.
This is the easiest way I've found the bleed the lines on this particular style tractor after a filter change.
This is the easiest way I've found the bleed the lines on this particular style tractor after a filter change.
Thank you. There is a bleeder valve at the pump and I do have it open when using the manual pump on top of the primary filter.
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Be sure you are getting good flow of fuel out of the water separator. Kubota tractors, (Almost ALL of them!) are prone to blocking off in the 90 degree fitting where the fuel enters the separator. There is no filter before there so anything that gets into the tank can get into that fitting and plug it up. I have seem this MANY times and the symptoms are just as you described. You pretty well have to take the whole separator off to have a look.
The water separator housing has a history of getting debris lodged in passageways. Does separator bowl have a pocket of air in bowl? My old M4900 had a tiny screen that was plugged in fuel shut off valve that caused lack of power problems.
Thank you for your response. It was in fact a small piece of debris in the housing as you and the others who replied, described. I am up and going again. Ty.