What RPM's should a Kubota B8200 engine Idle

[plumber mechanic]

In bought a used Kubota B8200 diesel tractor and the engine idles at about 1,000 rpm's. Engine model is D950-A-DT. Is that about the right rpm's or should it be lower? Can't find any mention of it in the owners manual.

Also trying the figure out the year this tractor was made. The manufacturer plate does not show a serial number only that it is a B8200 Kubota model with a D950-A-DT engine. How do figure out the year manufactured???

 

[GreensvilleJay]

as a reference ??
WWW.Tractordata.com says 1983-1990........

 

[85Hokie]

Diesels tractors seem to not "balance" well at a very low idle.

Diesels are NOT like car engines in the fact that they do not rev up to 6k rpm nor idle at 550 rpms.

of the 5 Kubota diesels I have owned - all of them idled at 1200 to 1500 rpms at idle. And if cold I bump the idle up a little bit higher to make it "smooth"

AS for your B8200 - I would not even worry about the idle - that sounds about perfect in my opinion.

 

[John D 2]

1000 RPM sounds right to me. Thats where my 2601 idles.

My last 2 green tractors (670, 3005) idled around that.

Only my 1025R was different. It was 1575 RPM at idle. Too fast. . .

Just one of the reasons I traded it for my 2601.

 

[plumber mechanic]

Thanks guys. I'll let it where it is.

 

[Killfast11]

mine idles at about 800rpm

 

[RBsingl]

3 cylinder inline diesel engines like that used in your B8200 will vibrate very badly at low RPM which is a primary reason for what sounds on paper like a high idle speed. Power pulses are 240 degrees apart and you will feel them at low RPM. The engine COULD idle lower but the rest of the tractor and the owner wouldn't like the result.

A 4 cylinder design is inherently smoother but even those typically have a fairly high idle speed. A lot of 4 cylinder car engines have used balance shafts, active engine mounts, and other approaches to hide some of the vibration even though the 180 degree power pulse "spacing" is far better than the 3 cylinder produces.

Fun fact: although your tach will show a pretty steady RPM, the crankshaft speed is constantly changing as it ramps up during a combustion event and slows between those events. The flashing CEL "misfire" indicator in passenger vehicles occurs when the expected rate of crankshaft speed change doesn't occur with each combustion event. GM (and others) do ongoing calibration of diesel engine injectors by changing individual injector trim to create equal changes in instantaneous crankshaft speed as each cylinder "fires".

Rodger

 

[Flintknapper]

mine idles at about 800rpm

My 3 cyl L2350Dt idles at about 700-800 rpm...but doesn't 'smooth out' until about 1100 rpm and the 'Sweet Spot' is between 1800-2000 rpm when running.

 

[plumber mechanic]

3 cylinder inline diesel engines like that used in your B8200 will vibrate very badly at low RPM which is a primary reason for what sounds on paper like a high idle speed. Power pulses are 240 degrees apart and you will feel them at low RPM. The engine COULD idle lower but the rest of the tractor and the owner wouldn't like the result.

A 4 cylinder design is inherently smoother but even those typically have a fairly high idle speed. A lot of 4 cylinder car engines have used balance shafts, active engine mounts, and other approaches to hide some of the vibration even though the 180 degree power pulse "spacing" is far better than the 3 cylinder produces.

Fun fact: although your tach will show a pretty steady RPM, the crankshaft speed is constantly changing as it ramps up during a combustion event and slows between those events. The flashing CEL "misfire" indicator in passenger vehicles occurs when the expected rate of crankshaft speed change doesn't occur with each combustion event. GM (and others) do ongoing calibration of diesel engine injectors by changing individual injector trim to create equal changes in instantaneous crankshaft speed as each cylinder "fires".

Rodger

Thanks Rodger.....good information.

 

[RBsingl]

Thanks Rodger.....good information.

You are welcome!

Rodger

 

[North Idaho Wolfman]

In bought a used Kubota B8200 diesel tractor and the engine idles at about 1,000 rpm's. Engine model is D950-A-DT. Is that about the right rpm's or should it be lower? Can't find any mention of it in the owners manual.

Also trying the figure out the year this tractor was made. The manufacturer plate does not show a serial number only that it is a B8200 Kubota model with a D950-A-DT engine. How do figure out the year manufactured???

Only way you will find out the year is look on the Clutch housing ( normally by your feet ) for a stamped serial number.
Take take that number to a dealer and see if they will tell you when it sold new.
Tractors year are when they are sold not made so f they can give you a year then you have it.
Otherwise it was made 1983 and 1990.