Temperature Gauge/Light

[mnyanmar]

I have a 1300d that I put a temp gauge on. What is the normal operating temp and what is considered the highest temp that the motor should be operated at before cooling it down. I have a new radiator and my cooling system works fine I just want to know what to look for on my temp guage. What temp is the warning light on the tractor set to go on at?

 

[Anonymous Poster]

If it has a thermostat, the engine should come up to thermostat temperature. If no thermostat, the engine will run cold. My 240D rarely goes over 120*, unless the radiator is plugging up with chaff.
It never hurts to cool a machine down if you've been working it for a while.

 

[gbirky]

mnyanmar,
The YM1300D has no thermostat, and no water pump. It is one of the early designs that relies on the thermosyphon effect to circulate the coolant. These tractors run much hotter than the Yanmars with water pumps. I wouldn't be surpised to see temperatures over 220F.

For the thermosyphon circulation to function, you need to limit the anti-freeze concentration to the minimum necessary to prevent freezing. 40% antifreeze and 60% water is the highest recommended. I think this requirement is mostly for summer operation, though if you use higher anti-freeze concentrations in winter, you probably should change to a lower concentration, or even just water for the summer.

 

[allenp]

I searched through a LOT of postings soon after I got my YM1700 and found that most users that had a tractor without a waterpump were observing temps in the range of 190-220F. The temperature will depend a lot on how the tractor is being used, ambient temperature, and angle of travel. I found out that on long downhill runs or off camber the temperature would increase by as much as 10-15 degrees.

If I remember correctly, the original temperature switch would turn on the light at 248F so as long as you stay below 230F, you should be ok.

Hope this helps.

Allen

 

[Kelvin]

Bottom Line: Make sure you have the proper rated radiator cap in good working order; as long as the pressure relief doesn't activate you're probably in good shape. Some of the Kubotas with the "thermo-siphon" cooling system (no water pump and no thermostat) have a whistle mounted on the end of the radiator overflow tube to serve as an overheat warning device.

I have a Kubota B7100 with the "thermo-siphon" cooling system. I did a calculation on this a long time ago and posted it on this board (on the first post I put in the wrong numbers and corrected it on a later post...). It seems like the maximum temperature was around 248F-250F assuming water only. I got to this temperature by taking the 212F water boiling temperature at sea level and adjusting (see <font color=blue>explanation</font color=blue> below) for the higher pressure that the radiator cap induces (which raises the boiling temperature). Adding in anti-freeze (50% maximum for thermo-siphon systems) would raise the maximum temperature even more.

I added a temperture guage to my B7100 and temperatures frequently are in the 220F range, and on hot mowing days it will reach 240 or 245F. Real scary (especially at first), but it's worked fine since the engine rebuild in 1998 (I suspect that the engine rebuild was required because the previous owner, an elderly lady whose husband had died a few years before she sold it, had used 100% antifreeze in it). After the engine rebuile with the new temperature guage, we put 100% antifreeze in it; it shot up to 230F within a couple of minutes of idle operation. We drained the antifreeze, PREMIXED a 50/50 solution and poured the diluted antifreeze back in and the idle temperatures were (and still are) around 190-210F.

Calculation <font color=blue>Explanation</font color=blue>: Basically take sea level pressure (14.7psi) and add the radiator cap rating (7 psi?) to get the total pressure in the radiator. Then go to a chart that shows the boiling temperature of water vs pressure and you'll come up with a temperature in the upper 240s. Those in higher elevations will have an even higher boiling temperature.

Kelvin