Kubota G5200 overheating

BMXER10 · Jun 14, 2010

After numerous attempts to fix this im at my wits end...

Got a g5200h, 1200 hours on it, 3 cylinder diesel. The mower runs great and fairly cool except when outside temps are over 90 degrees and humid. When its really hot outside and im running the mower deck the temp gauge slowly climbs to the hot side and begins to overheat.

So far I have: flushed the radiator, 50/50 mix with water wetter, new radiator cap and thermostat, smaller battery (sits right behind radiator), cleaned out the fins which were already pretty clean.

Several people said to check the mower deck to make sure its doesnt have a jammed pulley, but everything on the deck spins nice and free. The belts all look good and ujoint in front of the deck spins nice and free too.

Some even suggested there might be a head gasket leak. But im not getting any weird bubbling in the radiator fluid and it isnt turning dark at all.

Only other thing I can thing of is to run a extra electric fan in addition to the stock belt driven fan.

CCWKen · Jun 14, 2010

Check to make sure the fan belt is tight enough and there's no cracked blades on the fan. I've got a G4200 that I made into a custom ride. Not much Kubota left but the front axle, hood (extended), engine, cowl and seat. The rest was all fabricated. The rear end is hydraulic driven.

I call it the Kenbota!

Transit · Jun 14, 2010

I had a similar problem with my Jinma. What i found was a 4 inch gap between the top of the radiator and the hood. Hot air discharging from the back of the radiator was being drawn over the top into the front. Got some Storm King foam from Home-D and blocked off the gap. Everything is cool now.
You could also change the size of the pulleys, large drive and small driven, or have the radiator re-cored, more core tubes front to back.

banjodunn · Jun 15, 2010

G'day as transit said check for gaps around the radiator and seal them up if need be make a shroud that goes around the fan and seals to the radiator so that the air has to go through all the radiator. You may also need a fan with more blades on it so it will pull more air. When it is running and not too hot carefully feel across the radiator front and see if the heat change is uniform it should go from cooler at the bottom to warmer at the top but BE CAREFUL unfortunately some cooling systems don't cope well in warm and humid weather.

Jon

Egon · Jun 15, 2010

My Kubota B7100 had similar problems when working in hot weather. Somehow or other I felt the cooling system just was not large enough for the ambient temperature and loading. My only solution was to park and wait for cooler weather.

BMXER10 · Jun 21, 2010

After it got hot again this weekend I pulled it into the garage and took the radiator off completely.

Turns out that near the bottom of the radiator (the one part I couldnt see) it was clogged with very fine dirt. I hosed it out really good and its clear now.

Now im debating about taking the radiator to a shop to have it rodded and cleaned. There seems to be a decent amount of mineral build up. I would rather clean it myself to save some $$, but I dont want to waste time reinstalling it, only to have to take it in anyway.

milkman · Jun 22, 2010

BMXER10 said:
Turns out that near the bottom of the radiator (the one part I couldnt see) it was clogged with very fine dirt. I hosed it out really good and its clear now.

Good catch, I think that is a problem a lot of the times when people say, fins are clean and still overheats, there's a lot of space that is hard to tell if it's clean because of the shroud. If you can see mineral deposits, I think it would be a good idea and save you some work, to just have a shop clean and rod it and should be good as new. The G5200 was made in the '80's so you should get another 20 yrs out of it.