I am a new owner of a b2650 . The manual does not stipulate rpms for different operating conditions. What is the correct operating RPMs for example when using the bucket to move gravel and when operating the Box scraper. Is 2000 RPMs the right range.? Thanks.
rpm to operate tractor..
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85Hokie
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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
This is an age old question, and there is no right answer, however there are wrong answers.
Your machine was designed by someone to produce a certain about of horsepower and torque at a certain rpm. Each is machine different!
However, most of the people that come from the gasoline engine world see the relationship of throttle to work being done. You drive your car at 2000 rpm's when on the highway, and kick it to demand more power to pass someone.
On a lawn mower - the throttle is set to a limit that allows the engine to run near it's max RPM to cut grass etc. Most of us would not cut grass in an idle speed, the results would not be desirable!
Diesels work the same YET differently - most all of them have hydraulic pumps that need to be driven to achieve the desired results.
to answer your question in a more direct way - do NOT baby it, that will cause more harm than good, lean the other way - run it near wide open, it ain't gonna blow up, but will produce the power you need to do what you are doing in a timely manner...
now there are times when backing off the throttle is good idea......around your wife's flower beds is one, or if up against the house and you need a very delicate touch!
whatever is on the tach, run it about 90% of that and you will be fine.
the harder it needs to work, the harder you must work it.........if that makes sense......
new machines do NOT like to sit at idle long.......
Just like he said these motors are designed to operate at WOT. use more RPMs and don't worry lugging these motors will cause a lot more undue wear than running them at a higher RPM. Use enough motor to get the job done,, If your mowing, the like he said 90% of what the tech is reading,, I run mine WOT when mowing, as you play,,,errrr work I mean WORK with her you will find that happy sweet spot for the motor to work, Just don't lug it down,, And oh yeah pictures we love our tractor porn
Agree with 85Hokie.
Google "Diesel Slobber" and you will learn what happens to diesel engines when owners dont work them hard. The piston rings lose their seal to the cylinder walls and you end up with all kinds of blow by.
Working it hard does not just mean high rpm's but for example pulling a heavy trailer up hills, pulling a plow through the ground. You want to get high cylinder pressures to keep everything in top shape.
Dave M7040
Google "Diesel Slobber" and you will learn what happens to diesel engines when owners dont work them hard. The piston rings lose their seal to the cylinder walls and you end up with all kinds of blow by.
Working it hard does not just mean high rpm's but for example pulling a heavy trailer up hills, pulling a plow through the ground. You want to get high cylinder pressures to keep everything in top shape.
Dave M7040
I'd like to add, because I noticed you are a new owner (whom did not mention if you are a new operator). Beware the controls and pedal when you are operating "near wot". Go easy and watch the height of your fel (especially if full of material). Slight movements on the hyd control are in order because at higher rpm the hyd system cam move quickly and suddenly.
Do make a habit of running in low range if you "pack rat" (move) material in the fel and watch your cross slope. Many a new operator gets into trouble working too quickly, especially when learning a new piece of equipment.
Do make a habit of running in low range if you "pack rat" (move) material in the fel and watch your cross slope. Many a new operator gets into trouble working too quickly, especially when learning a new piece of equipment.
Yes I am also a new operator, and a farmer friend of mine gave me the same advice. Thank you for the advice, I am sure it will help me as I learn.
I'm not sold on a given method, I do know what works for me though. If I'm working the unit, loader or PTO, I run at PTO RPM's (not WOT).
If I'm doing speedy running around, I use 2000 RPM as it's traditionally the most efficient RPM for diesel engines as a whole. I don't know what the exact efficiency point is for these 3 banger Kubota's. I'm sure someone here does.
If I'm doing drag work (using the box blade or toting a trailer around, or very light loader work like local hauling of something), I use 1800RPM's and go up in RPM as needed with the foot pedal (essentially driving it like a car). Letting off the gas gives you a decent deceleration and you can stop relatively quick, change gears/direction with less stress on the clutch and corner nicely.
I almost never run at WOT. While there are over speed protections, etc. I'm leery of conditions that an engine could be pushed past it's safe limits mechanically. Those conditions would be fantastically rare, but possible. Giving a couple hundred RPM cushion doesn't hurt power-wise and actually saves a bit of fuel.
If I'm doing speedy running around, I use 2000 RPM as it's traditionally the most efficient RPM for diesel engines as a whole. I don't know what the exact efficiency point is for these 3 banger Kubota's. I'm sure someone here does.
If I'm doing drag work (using the box blade or toting a trailer around, or very light loader work like local hauling of something), I use 1800RPM's and go up in RPM as needed with the foot pedal (essentially driving it like a car). Letting off the gas gives you a decent deceleration and you can stop relatively quick, change gears/direction with less stress on the clutch and corner nicely.
I almost never run at WOT. While there are over speed protections, etc. I'm leery of conditions that an engine could be pushed past it's safe limits mechanically. Those conditions would be fantastically rare, but possible. Giving a couple hundred RPM cushion doesn't hurt power-wise and actually saves a bit of fuel.
I agree, one set rpm isn't right for every condition.
I'm sure there's lots of opinions on this but I also use the PTO rpm's for my max. I figure this is about the top of the power / torque curve and I don't really see any need to go any higher.
I'm glad someone mentioned "conditions" dictate operating rpm.
Many times I run at half throttle (I don't have a tach). OP mentioned two examples hauling gravel and box scraper. Hauling gravel on level ground vs up or down hill are two different animals. When hauling on flat to sloping ground I run more rpm than if hauling down-hill, and quite a bit more uphill. Always in low-range, and if on very steep ground I've actually backed down with a heaped bucket. Scraper I run the rpm's up pretty good, but not screaming unless the soil is rocky or heavy (clay). Once soil is moved and fine grading commences the throttle is rolled back down.
Many implements specify an operating rpm and by doing the math one can figure a clors *suggested* operating range. For example a post hole auger may spec a 3.18:1 Ratio and operating rpm of 300 300*3.18 would seem to indicate about 950 rpm. I'm pretty sure they are spec-ing min rpm. I'd read all literature and realize that most times the operator needs to make the call.
When I first learned it was if it's bogging down add more throttle.
Many times I run at half throttle (I don't have a tach). OP mentioned two examples hauling gravel and box scraper. Hauling gravel on level ground vs up or down hill are two different animals. When hauling on flat to sloping ground I run more rpm than if hauling down-hill, and quite a bit more uphill. Always in low-range, and if on very steep ground I've actually backed down with a heaped bucket. Scraper I run the rpm's up pretty good, but not screaming unless the soil is rocky or heavy (clay). Once soil is moved and fine grading commences the throttle is rolled back down.
Many implements specify an operating rpm and by doing the math one can figure a clors *suggested* operating range. For example a post hole auger may spec a 3.18:1 Ratio and operating rpm of 300 300*3.18 would seem to indicate about 950 rpm. I'm pretty sure they are spec-ing min rpm. I'd read all literature and realize that most times the operator needs to make the call.
When I first learned it was if it's bogging down add more throttle.
I'm glad to see this thread because I have wondered about this. I have no tach but when running my tiller it is wot. If I am driving from point to point it is just above an idle. If I am driving on the road it is wot. For everything else it is somewhere in between. I generally give it just enough throttle to get the job done.
I hope I am not damaging anything by not using wot for everything.
I hope I am not damaging anything by not using wot for everything.
comfun1 I'd not recommend running just over idle ever unless starting and just before shut-down. The way a hst transmission works is by pressurized hydraulic fluid. That fluid runs in galleries and supplies pressurized oil to bearings. The pressurized oil cushions and cools. THis is very important tothe longeviety of the unit. On the other hand the diesel engine is no friend of lugging and oil lubrication to bearings cam and rings and engine coolant (antifreeze) circulation is important whenever the tractor is working (if even running around). I'd recommend a minimum operating rpm of 2000 (if even moving from point to point) and incrementally more as the work effort increases.
My tractor has never seen wot during my ownership and seldom even 75 to 80% unless ripping or augering cemented soils.
My tractor has never seen wot during my ownership and seldom even 75 to 80% unless ripping or augering cemented soils.
I think the exact rpm for WOT and idle is different for different engines, 2000 rpm is close to pto 2426 on mine and I think wot is 2600. Warm up is recommended to be 1350. Auto throttle uses the whole range from idle up to 2600. Engine doesn't sound right to me running at idle so I don't leave it there long.
Your welcome.
Here's another one you may hear, "high idle" which is WOT. First time I read that it confused me because of the "idle" part.
Here's another one you may hear, "high idle" which is WOT. First time I read that it confused me because of the "idle" part.
I match rpm to proper PTO speed when mowing etc. With FEL work, a high RPM makes for a jerky response with lots of bounce. FEL work is more about feel, especially when moving and operating the FEL. I'm about half throttle.