What's a good engine idle speed for a small Yanmar "80" diesel engine?

[ThirdMan]

My FEL has almost no lift power at 1350. I usually have it running at least 1800 if I am moving the tractor around. It is has a much faster drive speed at a higher RPM. You say it will operate the attachments at 1350 but that is far below the PTO speed. The BH is much quicker when running higher than idle.

I just went an looked at the manual. Page 3-8 section (9) Throttle lever states, "Notice: Set the engine speed over 1500 rev/min for stability of hydraulic system while driving or working."

 

[mslisaj]

That's all correct for me too "Thirdman", I'm just curious about the idle speed. Where should the rpm be when I close the throttle. I think we have the answer of 900 that sounds good.

 

[ThirdMan]

Searching around a little bit for the JD 1025R (which has the same Yanmar 3TNV80F) there are a lot of opinions online on what the idle speed should be. The JD has an even higher idle speed at 1,500 RPM. I don't know which of those opinions are correct.

 

[tomplum]

You make some good points jdom, though the MT engines are different animals the ours. Our XJ seems to have a governed idle at 1100. Generally I don't get the shakes really unless after a cold start and for some reason drops into the 9's. The Yanmar reaches its peak HP at a higher RPM. My governed high speed is 2630. It will be neat to compare the two engines as far as vibration.

 

[Katahdin]

I've read the new EPA Tier IV Kubota Bs idle up there too, in the 1350-1450 RPM range.

So...I respectfully disagree with those who say mslisaj should tune her idle to 900rpm. I know you guys mean well, but the new emissions standards are changing the norm. The higher idles are keeping the engines warmer so they burn cleaner.

 

[Katahdin]

You make some good points jdom, though the MT engines are different animals the ours. Our XJ seems to have a governed idle at 1100. Generally I don't get the shakes really unless after a cold start and for some reason drops into the 9's. The Yanmar reaches its peak HP at a higher RPM. My governed high speed is 2630. It will be neat to compare the two engines as far as vibration.

The Yanmar engines are more square, they have a shorter piston stroke, so it makes sense they would get their power at higher rpms:

Bore vs Stroke
Yanmar 3TNV80F = 80x84mm
Mitsubishi S3L2 = 78x92mm

 

[Doofy]

I've read the new EPA Tier IV Kubota Bs idle up there too, in the 1350-1450 RPM range.

So...I respectfully disagree with those who say mslisaj should tune her idle to 900rpm. I know you guys mean well, but the new emissions standards are changing the norm. The higher idles are keeping the engines warmer so they burn cleaner.

My XR3135 idles at 800 RPM. During REGEN the idle is at 1100 RPM. First regeneration happened at 24 hours which surprised me because most of those hours were at PTO speed or a little less. Very little low idle time. Thought first regeneration would occur at around 40 hours.

 

[Katahdin]

My XR3135 idles at 800 RPM. During REGEN the idle is at 1100 RPM. First regeneration happened at 24 hours which surprised me because most of those hours were at PTO speed or a little less. Very little low idle time. Thought first regeneration would occur at around 40 hours.

Thanks for the info but this is not an apples-to-apples comparison. The 3TNV80F is a smaller engine that does not utilize dpf filters or regen, it must need a higher idle to meet the EPA emissions requirements.

 

[thepumpguysc]

I rebuild the injection pumps.. THE FACTORY SPECS SAY> 800-850 rpm..
but turn it what ever you want.. now that you know where the screw is.

 

[Doofy]

I rebuild the injection pumps.. THE FACTORY SPECS SAY> 800-850 rpm..
but turn it what ever you want.. now that you know where the screw is.

There lies the puzzle...if the factory specs say 800-850 RPM why was it set up to run at 1350? Very curious.