Had the same problem as tallyho8 is having and ended up being the fuel filter assembly. They have 4 ports on them, the 2 ports that are at a 90% angel are pressed in or something. The one on the left side moved a little and went to take the line off and it 90 came off the housing. Put a new assembly on works perfect. Hopes it helps
Yanmar loses power, slows down & kills
- Thread starter tallyho8
- Start date
- Views: 192021
kmartshopper
New member
- Joined
- Jun 5, 2025
- Messages
- 4
- Tractor
- Yanmar 2000, Yanmar 1700
New here ... hi 
I had a similar issue with my YM1700... running all day and shut down. Figured it was a fuel pump, so i swapped that, the filter, and the fuel line from the filter to the pump...
It will start to slowly bog out after running for a bit. The only way I can keep it alive is to loosen the banjo bolt and shake it ... if i leave it loose, it spills out plenty of fuel but the tractor will get power and run... Obviously this isnt a solution...
Doesnt matter if the banjo bolt holes are lined up to anything in particular, it doesnt want to function when tight... The washers on it are the same as before.. Ive tried removing the washers, or stacking them one way or another.. no dice..
Its not the fuel.. the sister YM2000 runs on the same juice and it runs like a top. Ive tried running it without a fuel cap ( i dont recommend) Weird... The next thing ill try is some other kind of banjo bolt to see if this one is just incompatible with the pump ( though its the same OEM pump replacement)
I had a similar issue with my YM1700... running all day and shut down. Figured it was a fuel pump, so i swapped that, the filter, and the fuel line from the filter to the pump...It will start to slowly bog out after running for a bit. The only way I can keep it alive is to loosen the banjo bolt and shake it ... if i leave it loose, it spills out plenty of fuel but the tractor will get power and run... Obviously this isnt a solution...
Doesnt matter if the banjo bolt holes are lined up to anything in particular, it doesnt want to function when tight... The washers on it are the same as before.. Ive tried removing the washers, or stacking them one way or another.. no dice..
Its not the fuel.. the sister YM2000 runs on the same juice and it runs like a top. Ive tried running it without a fuel cap ( i dont recommend) Weird... The next thing ill try is some other kind of banjo bolt to see if this one is just incompatible with the pump ( though its the same OEM pump replacement)
bmaverick
Super Member
- Joined
- Sep 17, 2013
- Messages
- 5,616
- Location
- Beloit-WI
- Tractor
- Yanmar YM2610 ■YANMAR GURU■ EXTRAORDINAIRE
The reason why I use Seafoam and/or Gumout Tune-Up. Whatever one is on sale at the time. The Gumout works a tad better overall. Diesel can have microbe build up in the fuel system. Even the metal fuel lines that can clog easily.New here ... hi
It will start to slowly bog out after running for a bit. The only way I can keep it alive is to loosen the banjo bolt and shake it ... if i leave it loose, it spills out plenty of fuel but the tractor will get power and run... Obviously this isnt a solution...
Doesnt matter if the banjo bolt holes are lined up to anything in particular, it doesnt want to function when tight... The washers on it are the same as before.. Ive tried removing the washers, or stacking them one way or another.. no dice..
Its not the fuel.. the sister YM2000 runs on the same juice and it runs like a top. Ive tried running it without a fuel cap ( i dont recommend) Weird... The next thing ill try is some other kind of banjo bolt to see if this one is just incompatible with the pump ( though its the same OEM pump replacement)
Last edited:
ponytug
Super Member
Welcome to TBN!New here ... hi
It will start to slowly bog out after running for a bit. The only way I can keep it alive is to loosen the banjo bolt and shake it ... if i leave it loose, it spills out plenty of fuel but the tractor will get power and run... Obviously this isnt a solution...
Doesnt matter if the banjo bolt holes are lined up to anything in particular, it doesnt want to function when tight... The washers on it are the same as before.. Ive tried removing the washers, or stacking them one way or another.. no dice..
It's not the fuel.. the sister YM2000 runs on the same juice and it runs like a top. Ive tried running it without a fuel cap ( i dont recommend) Weird... The next thing ill try is some other kind of banjo bolt to see if this one is just incompatible with the pump ( though its the same OEM pump replacement)
That sounds as if it is fuel starvation, but occasionally I've seen a clogged air intake cause almost the same symptoms. I would check the fuel line for an air leak, crack, or a piece of debris. You might need to get the entire line clean and dry, and look for a small weep. Did you check the tank for debris? Have you blown the line into the tank from the filter side?
+1 on a SeaFoam treatment. You can fill the fuel filter with it, run the engine briefly to get the SeaFoam into the injectors, and stop the engine to let it soak for a while (e.g. a day). I add the rest of the can to the fuel tank.
All the best,
Peter
kmartshopper
New member
- Joined
- Jun 5, 2025
- Messages
- 4
- Tractor
- Yanmar 2000, Yanmar 1700
Thanks for the suggestion.. I think whats going to happen is that I'll bushhog with the wounded goat until I burn off enough diesel.. then I'll drain the rest... I'll give it a shot to replace the fuel feed line from the tank and the return line.. let's see how that goes.. as for the tank.. there's no contaminants in there and the fuel floods out when I remove the banjo. I'll check back once I've gotten a bit further
ponytug
Super Member
@kmartshopper if you are going to go brush hog for awhile, I would add a can of SeaFoam to the tank now. It can't hurt, and may help.
All the best,
Peter
All the best,
Peter
kmartshopper
New member
- Joined
- Jun 5, 2025
- Messages
- 4
- Tractor
- Yanmar 2000, Yanmar 1700
So, i did replace the return line, and the tank to filter line.. pretty much everything is new now up to the injector hardlines from the pump. Of course i didn't tighten the banjo bolt and the topped off tank of red diesel decided to drain itself. I did get a new banjo bolt with a bleed screw from southern tractor. I also drilled out the return line at the tank for slightly improved flow.
Some folks are suggesting seafoam. that sounds great.. however thats not my problem.. the lines are clean. the tank is clean. So what happens is, the tractor will start to lose full power .. say about 1/2 then continue to drop in power. Ill lean over and loosen the fuel banjo bolt to the mechanical fuel pump.. ill shake the loose but still attached bolt, some fuel is spilling out but the tractor goes back to 100% power. if i tighten it,,, it will loose power as before. if i leave it semi loose, spittiing out fuel , it will stay at full power.
A may be a vacuum issue perhaps, but not from the tank,, ive run it with the tank with no cap and go through the same issues. The new pump might need calibration... ill have to dig into the manual and see if this is where im having issues... its possible that my fuel air mix is off, though i would suspect that it would be a factor from the moment i turn it on rather than over time.
Once i make it over to get some diesel, ill give her another run with the new lines and the new bleeder banjo.. If problems persist, its calibration time w the pump,. which i hear is not exciting
Some folks are suggesting seafoam. that sounds great.. however thats not my problem.. the lines are clean. the tank is clean. So what happens is, the tractor will start to lose full power .. say about 1/2 then continue to drop in power. Ill lean over and loosen the fuel banjo bolt to the mechanical fuel pump.. ill shake the loose but still attached bolt, some fuel is spilling out but the tractor goes back to 100% power. if i tighten it,,, it will loose power as before. if i leave it semi loose, spittiing out fuel , it will stay at full power.
A may be a vacuum issue perhaps, but not from the tank,, ive run it with the tank with no cap and go through the same issues. The new pump might need calibration... ill have to dig into the manual and see if this is where im having issues... its possible that my fuel air mix is off, though i would suspect that it would be a factor from the moment i turn it on rather than over time.
Once i make it over to get some diesel, ill give her another run with the new lines and the new bleeder banjo.. If problems persist, its calibration time w the pump,. which i hear is not exciting
kmartshopper
New member
- Joined
- Jun 5, 2025
- Messages
- 4
- Tractor
- Yanmar 2000, Yanmar 1700
Good news finally.. After a run for some off road diesel, she ran for about an hour.. at first it tried to bog, but i unscrewed the bleeder.. looks like there were some bubbles.. and not a problem after... i had to stop bush-hogging once the drizzle became down-pour and lightning... So, prob a combination of changing out the return line, boring out the return connector to the tank, the tank to filter hose and the new banjo bolt with the bleeder. I was on to something with shaking the banjo bolt around but prob wasnt getting rid of trapped air slowly making its way back up to the injectors.
I appreciate those that were helping with suggestions. Its good to have a good community that helps.
I appreciate those that were helping with suggestions. Its good to have a good community that helps.