This is obviously a rookie question. At what RPM should I operate my 15hp 3 cylinder B6200? It only has a front end loader and it's hydrostatic. Tack goes to 3000, I'm not a fan of over revving a motor. Especially a diesel.
RPM operating range
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85Hokie
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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
There are lots of people that operate at 40% 50% and so on, on my bx i find that it will run "fine" at 2500 rpms, out of 3400 wot, but....and this is a big but, if i need to do something "real" I will run it up to 3100-3200 and rarely up to 3400!
The hydraulic "pressure" is a direct result of engine rpm. In a former life around heavy equipment, like skid steers, excavators, etc.....boss told me never run at part throttle, alway run at "x" which was about 90% wot.
Every engine is different and designed to be run at that "sweet spot" If you find what your PTO 540 rpm's ='s on your tractor, that would be a good starting point. If I had to guess at a magic number, I would say about 2700 rpms would be a good number on a 3000 rpm wot machine.
Your engine has a governor, you can't over rev it unless there is a mechanical issue with the injection pump, or you are in gear coasting down a big hill and let the engine rpm get above the governed rpm level. Rest assured that if Kubota set the maximum rpm at 2600 or 2800 rpm, up to that rpm is not considered over revving the engine.
However, I generally run less than maximum governed rpm as I am not cutting grass, where I need the blade speed. For me, to keep engine fuel consumption down as well as noise, I run 1500 - 1900 rpm for most of my loader work.
So there is a significant difference between over revving the engine, which is pretty hard to do unless you find a big hill and let the engine go past the governed rpm, and operating the engine at a higher rpm level than necessary to get the job done.
As previously noted, a cruise 90% of max rpm is a good rule of thumb, but that falls under the rpm too high for the job, it still does not mean that you are over revving the engine by operating it above 90%
David
However, I generally run less than maximum governed rpm as I am not cutting grass, where I need the blade speed. For me, to keep engine fuel consumption down as well as noise, I run 1500 - 1900 rpm for most of my loader work.
So there is a significant difference between over revving the engine, which is pretty hard to do unless you find a big hill and let the engine go past the governed rpm, and operating the engine at a higher rpm level than necessary to get the job done.
As previously noted, a cruise 90% of max rpm is a good rule of thumb, but that falls under the rpm too high for the job, it still does not mean that you are over revving the engine by operating it above 90%
David
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great advise. Thanks. I seem to like the sound at about 2000 rpm and it works ok for me. But as I've said in other posts, my hydraulics are pretty slow and when using the loader in heavier stuff I really need to be at Least 2500 to get the hydros moving. I don't know why but it sounds to me like its revving too high so once I back out of the pile I pull it right back to 1900-2000.
I have to agree, anything above about 1900 rpm on my L3200 and its just plain too noisy. For the life of me I can't understand why basic sound proofing is not available, either standard or optional. Which is one reason I have no PTO powered implements.
I detest running loud equipment, especially when applying just a little well known engineering it could be quieted down.
David
I detest running loud equipment, especially when applying just a little well known engineering it could be quieted down.
David
If you are questioning this to get more hours out of the engine before overhaul, there is another factor - temperature. Posted on another site one of the members was a farmer mechanic for many tractors. They had two types of tractor uses. They were field tractors and chore tractors. Field tractors ran all day and chore tractors did intermittent work, with intermittent running. Nothing was told about engine RPM's but my guess the field tractors were run at higher RPM for getting their job done, as compared to chore tractors. Their experience was the field tractors ran for twice the hours as compared to chore tractors before re-building was needed. So, apply that to your jobs and apparently RPM is not critical, but starting and stopping were more important.
Lugging a diesel is also bad for it. Because it "sounds" too fast isn't really a scientific reason. I'd never run one under 2K and that would be for very light work. You will not hurt them running them at 2500-3100. Just use a LITTLE more fuel. I can tell you in the Diesel VW world cars that are pussy-footed around die an early death or never run right. Those that get the beans on a regular basis drive better and last longer.
Remember, these motors are designed to do this. Run flat out for their lives.
Remember, these motors are designed to do this. Run flat out for their lives.
85Hokie
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Staff member
Lifetime Member
Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
I pulled the Bx25 out today, thought about this thread, started moving around at about 2200 rpms........lugging is an understatement! I thought I heard the engine say "feed me" and got her up to about 2900 - 3000, told myself ....this is how they built it, this is where to run it !
Thanks for all the feedback. I don't know why, but I seem to like the sound of 2000 RPM. There is line at 2500 where the tack goes from 1 - 2 - 2500 - 3. So 2500 is probably the rpm they recommend. The machine does seem to perform better at 2500 so I'll probably start operating at that range from now on. I just recently sold my 7.3l powerstroke diesel in order to buy the kub.(which I had for 9 years) And I didn't like hammering on that either. But I'll have to come to terms of running the equipment where it was meant to be run. From the reading I've done, the newer bx series run at higher rpm so 3100 is at the max of my limit at full throttle. Just wanted to make sure i wasn't running the ol girl flat out.
My L3200 also likes about 2000 RPM but I've taken it as high as 2400 where it felt like I wasn't getting the work for the speed, like I was transitioning from torque to HP, which is important for some implements, generally non-ground engaging ones that need higher PTO speeds.