Temp on my Yanmar 1500

Anonymous Poster · May 28, 2003

Took the tractor out to do some tilling. Had put a temp gauge on a few days ago. After tilling about 15 nmin I notice the temp over 250 deg. Tractor did not get hot. I pulled the gauge and checked with boiling water and water boil at 212 on the gauge. What going on???

Inspector507 · May 28, 2003

Under pressure, water boils at a higher temp. 250º may be OK.

jimstractors · May 29, 2003

The 1500 has no water pump. To cool correctly, make sure you have 25-40% anti-freeze to water ratio, no more. Also, make sure system is full, with no air pockets.
Jim

allenp · May 29, 2003

In my opinion, 250F is too hot. Like as been posted several times before, you probably need to flush the cooling system, make sure fins are cleaned, and limit the coolant to 20-30%, and so on. According to what I was told sometime back, if you had the original water temperature sensor, the light should come on at 248F (+/- 5.4F) and go off at 233F (+/-5.4F). So based on temperature you were reading, you were right at the overheating point.

Anonymous Poster · May 30, 2003

The highest temp I've got my YM1500 up to so far is 235.
I've read that 230 is OK, and I've also read about the "idiot" light coming on at 248.

If you have a screen over the radiator, clean it often. It makes a big difference. Also, it seems like the engine actually runs cooler (a little) if you run it around 2200 RPM. I assume faster engine speed equals more air flow (fan) equals lower temp.

I am running straight water with no anti-freeze as it's not necessary (Florida)and straight water cools better. My next project is an engine and radiator flush. I'll replace with straight distilled water and "water wetter" which is supposed to lower the operating temp.

Anybody use "water wetter"?

Bird · May 30, 2003

Rick, I know you don't need antifreeze to prevent freezing, and maybe straight water is the right thing for you, but I guess you know that antifreeze also contains a lubricant (good for the water pump) and rust inhibitors (good for the entire engine) and will raise the boiling temperature. So I thought everyone ran antifreeze year round in everything now-a-days.

Of course, I'm old enough to remember when cars didn't have pressurized cooling systems and coolant recovery jugs, and lots of people put antifreeze in the radiator in the Fall, drained it out in the Spring, and put in fresh water, but they also usually added a can of water pump lubricant/rust inhibitor. If they didn't . . . ., well, we sold water pumps, too. /forums/images/graemlins/laugh.gif

pruntyc · May 30, 2003

<font color="red"> </font> Also, it seems like the engine actually runs cooler (a little) if you run it around 2200 RPM. I assume faster engine speed equals more air flow (fan) equals lower temp.

<font color="black"> </font> You should be running it at 2200 to 2400 all the time, as that is what they are meant to be run at when working

gbirky · May 30, 2003

Bird,
The 1500 doesn't have a water pump, so the lubricant is not necessary. The rust inhibitors would be useful. The problem is that using antifreeze in these engines without waterpumps inhibits the natural convection (thermosyphon effect) that the engine relies on to circulate the coolant. As long as the rust inhibitor doesn't also inhibit that effect, then it's OK. For me, I'd rather run the risk of rust and deal with its effects, than overheat the engine and warp or even crack the head. As long as the system is clean, and a proper radiator cap is installed, it should cool as it is supposed to with just water.

allenp · May 30, 2003

Regarding lower temps at 2200 rpm, I obersved the same on my YM1700. It seems that 2000-2200 would keep the temperature down by a good 10-20 degrees.

Bird · May 30, 2003

Gregg, I had a Kubota without a water pump, too; same type cooling system. It came from the dealer with antifreeze in it, but I know you don't want to go too high a percentage of antifreeze for it to work properly. I wasn't sure which cooling system your Yanmar had. And pure water may be the right thing, I don't know. I just know I'd be concerned about rust, and I also don't know what effect, if any, adding rust inhibitor to the water would have, but doubt that it would hurt anything at all.