743 Overheating problem

[kap258]

I have an old 743 that I just repalced the Kubota V1702 with a newly rebuilt one. For fear of overheating the rebuilt engine I replaced the temperature guage so I would know exactly what temperature I am operating at. It is getting to 250 degrees after about 15-20 minutes of running at full power. I have checked the thermostat and it is opening at 180 degrees as designed and I had the radiator cleaned and rotted out and I am still running hot. I was told by the company the engine came form that it should operate at 220-230 degrees. I have also checked the accuracy of the temp guage. When I filled the radiator it only took 2 gallons according to the manual it should hold 13 quarts of fluid and after running it up to 250 degrees and checking the radiator it is still full. Anyone have any ideas to keep it cool@

 

[Tazza]

Did you also replace the temperature sender? I had one that rocketed up to red when i was using my machine and i thought the engine just got cooked, but luckily it was just the sender.
If the engine was rebuilt and you changed the thermostat (which they should have done with the rebuild) the only other thing is the water pump. They should have also checked it and replaced the seals/bearing.
Good luck

 

[kap258]

Did you also replace the temperature sender? I had one that rocketed up to red when i was using my machine and i thought the engine just got cooked, but luckily it was just the sender.
If the engine was rebuilt and you changed the thermostat (which they should have done with the rebuild) the only other thing is the water pump. They should have also checked it and replaced the seals/bearing.
Good luck

Yes, I replaced the sender and the water pump was supposed to be rebuilt. Thanks.The only thing I have not replaced are the 2 radiator hoses. After talking it over with friends I was told a hose may be collapsing. I am going to try that today.