v 2203 overheating

[treemover]

Have a jacobsen hr 5111 with thus motor in it. keep in ming this is an auction special! Motor is supposedly rebuilt(seems to be correct), just installed new injector, thermostat, rad cap, radiator, rebuilt injection pump. Prob is that it is overheating, only under a load takes about 15-20min to get to 220-230. shut down mower let it sit at any engine speed and it cools down. at idle it will get under 130. I am a little stumped. Not using water, exhaust and oil clean. I think water pump is ok since it cools down.

Thanks in advance

 

[RDR]

I always go with the simple things first. Is the fan belt tight? With a new thermostat it shouldn't drop to 130. Even though it is new it might be stuck part way open and not opening up when it needs to. I would pull it and run it to see if it still overheats. If it does you might have a cracked head that is letting exhaust into the cooling system. It won't let it cool as well as just coolant.

Don't let anyone tell you it will run hot without restriction like having a thermostat in it. That is ignorance of 40 years ago. Guys I raced with would put a washer with a small hole in it to restrict the coolant flow. This causes steam pockets to form and steam doesn't cool like water. Good luck.

Also, could you tell me the number on your starter and who it was made by? I have an engine that was in an ST5111 and need the starter number.

 

[Dmaxdude]

Have a jacobsen hr 5111 with thus motor in it. keep in ming this is an auction special! Motor is supposedly rebuilt(seems to be correct), just installed new injector, thermostat, rad cap, radiator, rebuilt injection pump. Prob is that it is overheating, only under a load takes about 15-20min to get to 220-230. shut down mower let it sit at any engine speed and it cools down. at idle it will get under 130. I am a little stumped. Not using water, exhaust and oil clean. I think water pump is ok since it cools down.

Thanks in advance

Did you find a solutoion for this problem? I am stumped with the same overheating symptoms with my HR 5111 with the V2203 Kubota engine.
Thank you