Oil & Fuel New to me YM2500

[ponytug]

Congratulations on finding a cause, and I hope it is the problem!

One trouble with old o-rings is that they are usually not close to the original size. I am always staring at the old one and a handful of new ones going "would this be a better fit, or...." drives me nuts, but that's probably why I have a bunch of o-ring sets in nitrile and regular rubber.

All the best,

Peter

 

[Brokeodie]

Yes absolutely, i picked up a Viton set which is better for the biodiesel. Which is pretty much the norm around here in the diesel pumps. Buna end will apparently swell with biodiesel. So the tractor thru the clear lines i could see bubbles but as i tightened down the clamps the bubbles started going away and seems to be idling better..

For those who are curious this is the set i picked up. Viton O-Ring Kit, 180 Pc.

 

[Brokeodie]

So today i was able to bush hog some and it worked well. Oddly when i made a turn the motor would slow down and then pick up speed. On the straights there was no power loss even though I was cutting thru 4ft high weeds, grass, and hard bushy material. I was also able to get it to low idle although if i press the pedal it speeds up but then overshoots the idle and dies. Baby steps.

Here is a video of it idling although it's lower than it's supposed to be.

New video · Sunday, Sep 19, 2021 ð¬

Tap to view!

photos.app.goo.gl

 

[ponytug]

That is great news!

With the motor slowing down in a turn, I wonder about how the fuel tank is vented and whether it could be clogged. Have you looked for debris in the fuel tank and fuel line to the fuel filter that could be shifting during a turn?

+1 on Viton for biodiesel.

All the best,

Peter

 

[California]

I often bump the rod that goes from the foot pedal up to the throttle linkage. Could this be the issue in your turns?

 

[Brokeodie]

So I have a random request, Does anyone happen to have a video of a 3cyl yanmar pressing the accelerator and showing response of it speeding up and slowing down. I know on mine I can press it and there is a significant delay and when I depress there is a delay in deacceleration.

Any advise would be helpful. I am going to set the high idle and make sure it is set as well this weekend.

 

[bmaverick]

So I have a random request, Does anyone happen to have a video of a 3cyl yanmar pressing the accelerator and showing response of it speeding up and slowing down. I know on mine I can press it and there is a significant delay and when I depress there is a delay in deacceleration.

Any advise would be helpful. I am going to set the high idle and make sure it is set as well this weekend.

Delay? really? I have no delay in mine. Guess I'll have to do a vid over the weekend.

You have the manuals right? Those links did help you find them OK.

Setting the high idle should be per the spec page in the Yanmar parts manual or in the TM1192 service manual for the JD850/950/1050. The TM1192 goes into great detail how to do this. BUT, note, the JD model has a pivot lever that allows the throttle to flip the direction of slow to fast. Thus, the air cleaner assy and the throttle between the two machines is the slight difference other than green vs. red.

 

[Brokeodie]

long time no update.

so I took the governor linkage cover off to inspect and it was LOOSE!!! :-/ but it could have been worse if the little nut fell into the motor so I am thankful to have caught it. Ok so looking at the repair manual it says there is supposed to be a mark on the sliding rail of the fuel pump but I am not able to find the punch mark on the slide so not sure what to do. any advise would be appreciated.

 

[bmaverick]

long time no update.

so I took the governor linkage cover off to inspect and it was LOOSE!!! :-/ but it could have been worse if the little nut fell into the motor so I am thankful to have caught it. Ok so looking at the repair manual it says there is supposed to be a mark on the sliding rail of the fuel pump but I am not able to find the punch mark on the slide so not sure what to do. any advise would be appreciated.

Snap a pix of the gov linkage cover. If it has no-gasket, I can take mine off too, measure from where my machine is set to on the sliding rail. This way, you can set your at the same distance and all should be good then.

I did take a vid of the 3T80 at ideal, and then ramped up every 500 rpms to 3,000 and finally lowered back to idle. The trouble is, it's AVI format and is 80Mb.

Yes, glad you looked at the governor linkage rod. On my old JD850 3T80 engine, the diesel mechanic bent the rod. So the idle was a sporadic yo-yo. In time, the engine could only be run in full throttle and it died.

Glad you found the problem. Let's get it solved.

 

[bmaverick]

long time no update.

so I took the governor linkage cover off to inspect and it was LOOSE!!! :-/ but it could have been worse if the little nut fell into the motor so I am thankful to have caught it. Ok so looking at the repair manual it says there is supposed to be a mark on the sliding rail of the fuel pump but I am not able to find the punch mark on the slide so not sure what to do. any advise would be appreciated.

So what page in the repair manual? I looked at Section 50 Group 20, and couldn't see it there. I'm still flipping PDF pages.

OK, Section 30 Group 10.13