My friend said I could use his 3110D if I could get it running.

Rock N Rth

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Jun 4, 2026
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The fat and skinny is that he ran it out of fuel and the let someone try to get it started. When I got to it the fuel line nuts on the front cylinder were buggared up at the injector and the fuel pump. The fuel filter was half full of air and no fuel as coming out of the fuel pump when the engine turned over.

I bled the fuel filter.
I removed the fuel lines from the fuel pump, and then loosened the fittings on the fuel pump until fuel flowed freely from each of them. I let them drip until I had about A half a gallon of fuel in the bucket. Then I tightened them up, set the compression release, and turned the engine over until fuel was squirting out of all three. It seemed like the fitting that goes to the front cylinder had stronger flow than the other two.

I attached a fuel lines back to the fuel pump, and then turn the engine over until fuel was coming out of the tops. It still seemed like front cylinder had stronger fuel than the other two. I snugged down the fuel lines and turned over the tractor.

It started right up but was billowing black smoke. It seems like the front cylinder is getting a lot more fuel and the other two. When I push the throttle all the way to stop, the engine continues to run and I have to use the compression release to shut it down.

Any thoughts will help.

Thank you,
Rock N Ruth
 
It sounds like the front cylinder is overfueling while the others aren’t getting enough, which explains the black smoke. Check all injector lines for blockages or leaks and make sure the fuel pump and governor are properly synchronized. The engine running past throttle suggests the governor or fuel cut-off isn’t responding correctly, so I’d advice you address that before putting it under load.
 
Yes, I came to the conclusion that the front cylinder was getting More fuel than it ought to, and the other two were not getting quite as much. There are no blockages in the fuel lines. I do not know how to check if the governor is synced with the fuel pump, Where is said governor on the Y-3110D? and how would running it out of fuel cause a synchronization problem?

I believe the run on is because the one cylinder is getting way too much fuel. I would really like to understand how the fuel pump works, it appears to handle pumping fuel and regulating fuel volume and timing.
 
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I wouldn't expect running it out of fuel by itself to cause a synchronization issue. What concerns me more is that someone was working on it afterward and the injector line fittings were already damaged when you got there.

If it starts and runs, timing is probably in the ballpark. I'd be looking closely at the injection pump rack and governor linkage to make sure nothing is sticking. On many Yanmars the governor is integrated with the injection pump assembly rather than being a separate external component.

The fact that it won't shut down with the throttle and appears to be overfueling one cylinder makes me wonder if there's a sticking rack, governor issue...or possibly a problem inside the injection pump itself. Before tearing into anything, I'd verify that moving the throttle to STOP is actually moving the fuel control linkage through its full travel at the pump. That may tell us a lot about what's going on.
 
All good information. Have verified, No. 1 cylinder is getting much more fuel that 2 or 3. Following the Yanmar manual, removed the pump and began inspecting it then accidentally dropped some parts out of the rack before indexing it. Ordered a new fuel pump. Will still attempt to reassemble the pile of parts I made, but unlikely to install it in the tractor.
 
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