A farmer friend of mine just changed his fuel filter & fuel/water separator on his M8200 Utility Special & can't get the tractor to start now. I think he said the tractor is a year 2000 model. He had loosened the new fuel filter & squirted diesel in the top of the filter w/ a bottle & thin tube then threaded it on before I got there & I primed the fuel filter 40 times & we tried to start it to no avail. I did some research & loosened the banjo bolt on the fuel injector pump crank but no diesel ever came out of this nut throughout the whole process of trying to start the tractor (it just cranks & cranks and we've tried a bunch of times). I then loosened 3 of the 4 lines at the top of the injectors to bleed them (can't get to the 4th one - may have to take off the hood, FEL, & a 2" dia breather? hose to get access to it). A little diesel does come out the 3 loosened lines when we try to start it but it still doesn't start, just cranks & cranks. He's 83 years old & has said this has always been a PITA when he replaces the fuel filter but never this bad. Any ideas/tips/tricks on how to get his M8200 started? Appreciate any help!!!
RjCorazza
Elite Member
I think if I had a mechanical lift pump like on the M8200, I would break the fuel line somewhere for a temporary electric lift pump. At least that way you're not putting the starter at risk.
My only troubleshooting suggestions would be to confirm that the lift pump is moving fuel by disconnecting the fuel inlet to the filter. Also check all fuel lines for cracks or pinhole leaks that would prevent adequate flow.
My only troubleshooting suggestions would be to confirm that the lift pump is moving fuel by disconnecting the fuel inlet to the filter. Also check all fuel lines for cracks or pinhole leaks that would prevent adequate flow.
I'm no mechanic & that's over my head 
When I loosened the fuel lines on top of 3 of the 4 injectors they were leaking diesel when he cranked it so wouldn't that mean the lift pump is working? Everything worked fine until he changed the fuel filter & fuel/water separator so I'm thinking it's "gotta be something stupid" Or maybe I'm clueless...
When I loosened the fuel lines on top of 3 of the 4 injectors they were leaking diesel when he cranked it so wouldn't that mean the lift pump is working? Everything worked fine until he changed the fuel filter & fuel/water separator so I'm thinking it's "gotta be something stupid"
Or maybe I'm clueless...
scootr
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I'm not a real mechanic either but, if you are only getting a little diesel out of the injectors lines then you are getting air out as well... baring an air leak, more of the same should work. Maybe try bleeding injectors one at a time?
RjCorazza
Elite Member
I'm no mechanic & that's over my head
When I loosened the fuel lines on top of 3 of the 4 injectors they were leaking diesel when he cranked it so wouldn't that mean the lift pump is working? Everything worked fine until he changed the fuel filter & fuel/water separator so I'm thinking it's "gotta be something stupid"
Well, there is a fuel shutoff valve on the water separator / filter... Is that turned back on?
Chewwy
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Found this googling “fuel prime for Kubota M8200.”
To fuel prime a Kubota M8200, first, open the manual primer pump lever on the fuel filter housing to force fuel to the filter and remove air from that stage. Next, loosen the bleed screw on the fuel filter housing and continue pumping until a steady stream of fuel without air bubbles comes out, then tighten the screw. If air remains in the injector lines, loosen the fittings on the high-pressure lines at the injectors, crank the engine with the throttle wide open until fuel squirts out, then tighten the fittings.
Step-by-Step Fuel Priming
To fuel prime a Kubota M8200, first, open the manual primer pump lever on the fuel filter housing to force fuel to the filter and remove air from that stage. Next, loosen the bleed screw on the fuel filter housing and continue pumping until a steady stream of fuel without air bubbles comes out, then tighten the screw. If air remains in the injector lines, loosen the fittings on the high-pressure lines at the injectors, crank the engine with the throttle wide open until fuel squirts out, then tighten the fittings.
Step-by-Step Fuel Priming
- Fill the Fuel Tank: Ensure you have plenty of fuel in the tank.
- Locate the Primer: Find the manual fuel pump lever on the fuel filter housing.
- Prime the Pump: Pump the lever manually until it feels resistant, forcing fuel and purging air from the primary fuel system.
- Locate the Bleed Screw: On the top of the fuel filter housing, find the bleed screw.
- Bleed the Fuel Filter: Loosen the bleed screw slightly to allow fuel to flow.
- Pump Until Steady Fuel Flow: Continue to pump the manual primer lever until a steady stream of fuel without any air bubbles emerges from the bleed screw.
- Tighten the Bleed Screw: Once you have a steady fuel flow, tighten the bleed screw.
- Bleed Injector Lines (If Needed):If the engine doesn't start after the above steps, you may need to bleed the injection lines.
- Loosen Injector Lines: Loosen the fittings on the high-pressure lines where they connect to the injectors at the cylinder head. A second wrench can prevent twisting.
- Crank the Engine: With the throttle wide open, crank the engine.
- Watch for Fuel: Crank until you see fuel squirt from the loosened lines.
- Tighten Lines: As soon as you see solid fuel without air bubbles, tighten the fittings.
- Attempt to Start: Try to start the engine. It should now start and run.
leonz
Super Member
The diaphragm on the lift pump is probably shot and has torn and cannot lift the fuel.
That is ninety nine percent of trouble with an indirect injection engine like the Duetz,
Hatz, Kubota and Yanmar engines as there is a cam that pushes the plunger to deliver
fuel to the indirect fuel injectors.
I would suggest to your farmer friend that he should find out if the diaphragm pump
can be replaced with a plunger hand pump on his mules engine before he purchases a
replacement diaphragm fuel pump as the plunger pump will push the fuel with more
pressure when manually priming it.
That is ninety nine percent of trouble with an indirect injection engine like the Duetz,
Hatz, Kubota and Yanmar engines as there is a cam that pushes the plunger to deliver
fuel to the indirect fuel injectors.
I would suggest to your farmer friend that he should find out if the diaphragm pump
can be replaced with a plunger hand pump on his mules engine before he purchases a
replacement diaphragm fuel pump as the plunger pump will push the fuel with more
pressure when manually priming it.
Chewwy
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Thanks guys. We finally got it yesterday afternoon. Problem was just dang air in the lines. Broke 3 of the 4 (couldn't get the wrench to the 4th) fuel lines at the injectors loose & cranked a good bit here & there while also priming the push prime on top of the fuel filter & loosening/tightening the bleeder bolt on the injector pump (which by the way never had diesel come out of it???). Funny how there are different varients of "options" on the 8200, his doesn't have a bleeder valve on the fuel filter assy on his tractor & he hadn't turned the fuel shutoff valve off when he cleaned the fuel/water separator. Guess getting the air out of the lines was just way more of a PITA than he's ever had... Thanks again!
