CK20 Running hot

[ustmd]

SwedeSpeed,


Based on your comments, you look pretty sophisticated, so I hesitate to mention this, but I always try to check the dumb stuff first. On my 27, the screen on the radiator and on the inlets for the hood get clogged with grass and I have the exact same symptoms. A quick blow off cures the problem.

 

[Coyote machine]

Just to be clear, I'm running a 60" finish mower, not a brush hog (Bush Hog is the brand name of the mower). According to the owners manual this should not be too big for the tractor. Thanks for the explanation regarding the pto speed. I was thinking higher rpms= more heat, your explanation clears that up.

Got it. Finish, not hog.
Heat does increase with load, BUT by running higher RPMs hopefully you effect 'cooling' by not letting the load applied by the mower's rotation cause the engine to lug. The higher overall speed of the blades of the mower, being led by the engine's increased RPMs, keeps everything spinning without creating excess heat. Things are in sync, essentially. The ratio of power output to demand: load is balanced and everything runs smoothly.
And the coolant when fresh, allows heat to be drawn out of the radiator by the fan, and keeps the head and block in the correct range of temperature the engine and cooling system are designed to deliver.

 

[ritcheyvs]

Maybe some of you HST folks can add to this comment. When mowing, you really want to run your engine at (or close to) the PTO RPM indicated bu the red triangle on the tach. That produces the pto shaft RPM the mower (or rotary cutter) needs to work well. The heat produced by a Diesel engine is almost directly proportional to the power delvered to the output shaft. If the RPMs are too low, the engine may be able to produce the required power (hence heat) but the fan and water pump will run slower so the engine may run hotter. With my gear tractor, I run the throttle up to the red triangle and then select the gear that produces the desired forward speed (typically 1-high or 4-medium). I presume HST machines work the same except you "select" the "gearing" with the pedal.

 

[Coyote machine]

All true, except HST 'gear selection' is via the range shift lever, which has to be selected BEFORE moving, no synchromesh on the Kioti's at least. Most brush hog or finish mower cutting, or even mid-mount, if so equipped mowing would be in either low or medium range, never high. PTO speed, indicated by the red triangle pointer on the RPM gauge, would be the optimum point at which to have the engine revving for the best results in cut and engine/PTO drive function, and consequent cooling by fan and water pump.

 

[oldpilgrim]

Correct about setting the manual gear first, but I'm sure he was referring to the 'infinite" gear selection my pressing or backing off the HST pedal.

Set the engine speed, press the pedal to the appropriate hydraulic "gear".

 

[Coyote machine]

Correct about setting the manual gear first, but I'm sure he was referring to the 'infinite" gear selection my pressing or backing off the HST pedal.

Set the engine speed, press the pedal to the appropriate hydraulic "gear".

There are 3 range selections on a DK-40 HST. Low, med, high. Once one is selected on the range lever, then the forward or reverse pedal and throttle lever determine over ground speed in concert with the terrain. Pushing harder on the forward pedal does not equate to greater over ground speed in all cases, sometimes backing off the pedal allows the HST to give the most power to turn the wheels.
There aren't infinite 'gears', merely infinite pedal pressures that can be applied by the OP. Too much pedal pressure renders the HST unable to transfer more power to the wheels unless the terrain changes, or the load on the tractor changes, or the RPMs are increased to better handle the load. Or one can select a better range like low from having been using medium, to increase torque applied to the wheels.

 

[oldpilgrim]

pressing the pedal more does make the ground speed go faster until you hit a resistance, as a hill, just like with a standard geared machine. Letting off on the pedal in effect down shifts, just like you would do manually in a geared machine. I know there are no internal gears in a hydro, just the L M H lever that adjusts the gearing in the wheels, but the hydro does indeed have an infinite number of variations in engine speed to read end rations...there for the term 'infinite gears' is a good description even though gears are not involved.

If you don't like the term 'infinite gears' complain to the manufacturers about it. It's the terms they use. See their brochures and even the descriptions on tractordata.com

 

[Coyote machine]

Marketing brochures and Tractordata don't make it so. There is no downshifting, in a hydro, again a misnomer applied that only confuses what its actually happening.
This is what I actually said, not what you commented on: "Pushing harder on the forward pedal does not equate to greater over ground speed in all cases, sometimes backing off the pedal allows the HST to give the most power to turn the wheels."

Here is some of what you wrote: ..."the hydro does indeed have an infinite number of variations in engine speed to read end rations...there for the term 'infinite gears' is a good description even though gears are not involved."

What I interpret that to mean is the following: ....the hydro....has an infinite number of variations in engine speed to *REAR end RATIOS...THEREFORE...the term....."

*Caps are my corrections to what I believe you meant to say.:confused3:

You're entitled to your opinion as to 'infinite gears' usage in this application. Let's agree we're going to disagree on this and leave it as is.

 

[SwedeSpeed]

My tractor is not HST. It has 6 forward gears and two reverse. I did a little more mowing over the weekend, tried it out at higher rpm. Unfortunately, higher rpm made more heat rather than less. Temp indicator climbed to just over half way between midpoint and red.

 

[TJP89]

My tractor is not HST. It has 6 forward gears and two reverse. I did a little more mowing over the weekend, tried it out at higher rpm. Unfortunately, higher rpm made more heat rather than less. Temp indicator climbed to just over half way between midpoint and red.

What? I thought all CKs were a shuttle shift. 2 range, 4 gears, F/R shuttle, for 8F and 8R. Someone straighten this out?

Your temp problem now seems to be actual, not a gauge issue. What gear/range are you mowing in?