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Discussion Starter #1
Just a short post to get some opinions about throttle. In several places in the manuals it states running a low throttle for long periods of time may cause premature wear. There is also a recommended throttle setting for mowing lawn and that has a little wiggle room.

What is the rule of thumb for throttle for various jobs. Plowing, Snowblowing, Mowing (I assume anywhere in the marked zone), using a loader?

Lastly, is hydrostatic pressure directly related to RPM's?

Thanks,
Chris
 

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Hello. When mowing or using the pto you want the throttle set on the throttle setting on the rpm gage. It is what JD has set the rpms at to run the variuos pto required implements. If you run the pto at a lower throttle or over it then you take a chance of damaging someyhing.

As far as doing regular work I vary the throttle speed. The harder the work the higher the throttle. Thats my motto. I will ususally set the throttle about halfway if I am just driving around doing light stuff. Plowing or digging with the fel or the backhoe where I am digging or working her hard then I will crank the throttle up to the setting on the dash. I will also crank it up if I am carrying something really heavy in the fel.

And to answer your question more throttle does boost the hydro. To see what I mean drive the tractor at a low rpm and without changing the pressure on the pedal crank the throttle up.

Have fun
 

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Just a short post to get some opinions about throttle. In several places in the manuals it states running a low throttle for long periods of time may cause premature wear. There is also a recommended throttle setting for mowing lawn and that has a little wiggle room.

What is the rule of thumb for throttle for various jobs. Plowing, Snowblowing, Mowing (I assume anywhere in the marked zone), using a loader?

Lastly, is hydrostatic pressure directly related to RPM's?

Thanks,
Chris
I think the fear with low throttle settings is that some might actually "lug" the engine with too little RPM and put some strain on components. I am sure you have seen someone operate a machine at idle and cause the engine to buck and run rough due to the load and lack of RPM's. That you want to avoid doing for sure.

I always run my gas engines at 1/4 throttle or more for anything which requires movement. I see you have the x739 so that't the Kawasaki gas engine like the one I am referring to in my zero turn and running the throttle 1/4 or more when moving. I don't know at what RPM's the hydro pump reaches peak pressure but I would imagine it's well below WOT, I would assume probably 1/2 throttle or so.

I had the John Deere service technician tell me last week that in his opinion, they are putting more and more pressure on the hydro pumps on these small machines with such things as 3 point hitches, FEL, hydraulic front lift attachments, etc on these small tractors. It is his opinion that is part of the reason for the higher idle speeds on these newer machines, especially the Yanmars (as compared to older machines with similar power). Also, some of the increase in RPM's at idle is to reduce the emissions on these small engines.

I asked if he is seeing issues with the Hydro pumps on the small machines and he said "No, but people start them up and hit the pedals while also lifting hydraulic components, all which puts a strain on the small hydro pumps". His point was instead of waiting a few seconds for the system to build pressure, everyone is using all of the demand often right after start up without any warm up or working into it.

In real cold scenarios, you will find the hydraulic system slow to react and even the lift levers and directional pedals much stiffer to move until there is some heat in the hydro fluid. It is a good idea when it's cold to allow the hydro fluids and system some warm up time instead of turning the key and hitting the levers and pedals immediately.

While you don't need excessive RPM's for light duty tasks such as light snow plowing or blowing, or easy mowing, when you get into taller grass, wetter, heavier snow, I always operate with more RPM's so whatever task I am doing, isn't putting a strain on the machine. While there aren't too many tasks which warrant running at WOT endlessly, somewhere in between in the RPM range is how I have always operated the machine. I mow at about 80% of max RPM's the majority of the time. I have found you don't get any better cut at WOT in normal conditions and I certainly don't utilize full ground speed at WOT as I am more concerned about a great cut quality than doing the task as fast as possible.

My neighbor has a D160 and he starts the tractor at WOT and he also shuts it off when at WOT, in fact, I asked him if his throttle moves because its always WOT. I suggested reducing the RPMS before turning the key off yet he continues. It's his to blow up in any method which suits him.....:laugh::lol: I even asked him if he would start his BMW at redline and turn the key off at the same and he seemed appalled to think I would suggest such a thing. But it doesn't seem to correlate to him related to his little tractor that it's not a good idea. Oh well.....:dunno:
 

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Discussion Starter #4
I think the fear with low throttle settings is that some might actually "lug" the engine with too little RPM and put some strain on components. I am sure you have seen someone operate a machine at idle and cause the engine to buck and run rough due to the load and lack of RPM's. That you want to avoid doing for sure.

I always run my gas engines at 1/4 throttle or more for anything which requires movement. I see you have the x739 so that't the Kawasaki gas engine like the one I am referring to in my zero turn and running the throttle 1/4 or more when moving. I don't know at what RPM's the hydro pump reaches peak pressure but I would imagine it's well below WOT, I would assume probably 1/2 throttle or so.

I had the John Deere service technician tell me last week that in his opinion, they are putting more and more pressure on the hydro pumps on these small machines with such things as 3 point hitches, FEL, hydraulic front lift attachments, etc on these small tractors. It is his opinion that is part of the reason for the higher idle speeds on these newer machines, especially the Yanmars (as compared to older machines with similar power). Also, some of the increase in RPM's at idle is to reduce the emissions on these small engines.

I asked if he is seeing issues with the Hydro pumps on the small machines and he said "No, but people start them up and hit the pedals while also lifting hydraulic components, all which puts a strain on the small hydro pumps". His point was instead of waiting a few seconds for the system to build pressure, everyone is using all of the demand often right after start up without any warm up or working into it.

In real cold scenarios, you will find the hydraulic system slow to react and even the lift levers and directional pedals much stiffer to move until there is some heat in the hydro fluid. It is a good idea when it's cold to allow the hydro fluids and system some warm up time instead of turning the key and hitting the levers and pedals immediately.

While you don't need excessive RPM's for light duty tasks such as light snow plowing or blowing, or easy mowing, when you get into taller grass, wetter, heavier snow, I always operate with more RPM's so whatever task I am doing, isn't putting a strain on the machine. While there aren't too many tasks which warrant running at WOT endlessly, somewhere in between in the RPM range is how I have always operated the machine. I mow at about 80% of max RPM's the majority of the time. I have found you don't get any better cut at WOT in normal conditions and I certainly don't utilize full ground speed at WOT as I am more concerned about a great cut quality than doing the task as fast as possible.

My neighbor has a D160 and he starts the tractor at WOT and he also shuts it off when at WOT, in fact, I asked him if his throttle moves because its always WOT. I suggested reducing the RPMS before turning the key off yet he continues. It's his to blow up in any method which suits him.....:laugh::lol: I even asked him if he would start his BMW at redline and turn the key off at the same and he seemed appalled to think I would suggest such a thing. But it doesn't seem to correlate to him related to his little tractor that it's not a good idea. Oh well.....:dunno:
Much appreciated! I'm all about quality not speed. I'm looking forward to applying your theory in the spring on my lawn.
Thanks
 

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Discussion Starter #5
Hello. When mowing or using the pto you want the throttle set on the throttle setting on the rpm gage. It is what JD has set the rpms at to run the variuos pto required implements. If you run the pto at a lower throttle or over it then you take a chance of damaging someyhing.

As far as doing regular work I vary the throttle speed. The harder the work the higher the throttle. Thats my motto. I will ususally set the throttle about halfway if I am just driving around doing light stuff. Plowing or digging with the fel or the backhoe where I am digging or working her hard then I will crank the throttle up to the setting on the dash. I will also crank it up if I am carrying something really heavy in the fel.

And to answer your question more throttle does boost the hydro. To see what I mean drive the tractor at a low rpm and without changing the pressure on the pedal crank the throttle up.

Have fun
Exactly what I was interested in learning. Thank you sir!
 

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My neighbor has a D160 and he starts the tractor at WOT and he also shuts it off when at WOT, in fact, I asked him if his throttle moves because its always WOT. I suggested reducing the RPMS before turning the key off yet he continues. It's his to blow up in any method which suits him.....
Actually, other than starting the engine your neighbor is doing more things right than you think. The D160 operator's manual cautions against idling. Air cooled engines need lots of air flow. They are designed to provide optimum HP and cooling at around 3600 RPM at which they can run all day if properly cooled and lubricated.

The manual instructs to let the engine warm up a few mins but then everything else is pretty much WOT. Even shutting down. The manual instructs to run at high throttle without load for a few second prior to shutting down.

[h=3]Idling the Engine[/h]IMPORTANT: Unnecessary engine idling may cause engine or transmission damage. Excessive idling can cause engine overheating, carbon build-up, and poor performance.


Idling or low throttle operation while mowing, climbing hills, or towing could result in transmission overheating. always operate at full throttle once the engine is warm.


Do not operate machine with hood open. Hood must be closed for proper engine cooling and exhaust.

  • Engine is air cooled and needs a large volume of air to keep cool. Keep air intake screen on top of engine clean.
  • Keep hood closed when engine is idling.
 

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I think it's quite simple, idle only for warm up and cool down, and run whatever rpms the task at hand requires.
 

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The x500 series digital dash has a "best to operate" range. I'll run my 580 at lower speeds to putt around the yard or maybe pull the cart, but when mowing, moving dirt, tilling, or anything that requires horsepower it's WOT followed by a low speed cooling period when done.

Hydraulic pressure is of course RPM dependent. Running at low RPMs when operating hydraulics is simply asking for problems to happen.
 

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The x500 series digital dash has a "best to operate" range. I'll run my 580 at lower speeds to putt around the yard or maybe pull the cart, but when mowing, moving dirt, tilling, or anything that requires horsepower it's WOT followed by a low speed cooling period when done.
Running the engine at low speed to cool down is a bit of a misnomer as the engine needs RPM to move air. The fastest way to cool down the engine is to run at a medium fast speed but with no load.

That's why the X500 Operator's Manual lists this as the shutdown procedure:
[h=3]Stopping the Engine[/h]
  1. Stop the machine.
  2. Move throttle lever to half throttle position and allow engine to run at half throttle for several seconds.
  3. Turn key to stop position.


 

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The hydraulics question is a bit of word play.

When you start your machine the hydro system pumps it up to pressure within a second or two. On Deere machines that seems to be set somewhere near 2100-2200 PSI. You can adjust RPMs all day long and it won't have any effect on that pressure. Once that pressure is reached, anything above that causes the system to go into relief and the pressure stays where it was. If pressure drops the hydro pump pushes it right back up again.

What increasing RPMS will do is increase your hydraulic fluid flow rate. Implements that rely on the hydraulics will respond faster at higher RPM because more fluid is flowing to/from the hydraulic cylinders.
 
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