8070 got hot fast

I finally got my 2 year long project 8070 running the other day. I ran it for 5 to 10 minutes in the shop just for trial before putting the shields and stuff on it, and the heat guage moved off the cold side just enough to give me an indication that it works. Today I was going to put it to a light test, so I hooked the disc up to it. It was probably running for about 15 minutes by the time I got the disc hooked up and ready to give it a whirl. At this time the heat gauge was just up to the first mark. As soon as I started discing, the heat gauge started climbing very fast. I hadn't even gotten an eighth of a mile, and I had to stop and shut er down, cause the heat gauge was brushing up against the red. It definitly was not getting over worked, cause it was just playing with the disc.                                           The engine I put into the tractor is used one out of a 7580, and if I remember right had about 800 hours on a major overhaul. It had been sitting  for a few years, though, before I bought it. The radiator is a fresh re-cored one, so is to say "Just like brand new." When it over-heated, the top of the radiator, the upper radiator hose, and the thermostat housing were all very hot. The bottom of the radiator and the lower radiator hose were colder than a cucumber. The possibility that the gauge isn't reading right is real, but doubtful, because things seemed pretty hot. Thermostats were not changed, so it is possible they are stuck shut, but I doubt it, because it was hot on both sides of them. I don't know if that is an accurate assessment of them, though. Anyone have any ideas for me to check out? Thanks, Darrel

    Darrel i would say take the thermostats out an put then in hot water an see if they open, that wont coust much if they open .   Ron nca

is the lower hose clogged? maby the radiator has a rag or plug in the suction side.  sounds like the thermostats are opening or the rad would not be hot at the top.  sounds to me like there is no circulation.  i would check for blockages or as previously mentioned, air pocket.

I hate to jump on the band wagon, but I think what you have is a thermostat that is not opening all the way up, if it opens a crack you will get a hot upper hose, and top tank, but you will not get enough flow to do anything.  Also like Amos said, make sure all the foam is in the right place.  

Check for nest building materials that mice could have put up inside the block & head water passages. You mentioned the motor had been stored for some time. Was it stored removed from the tractor??   With rad. hoses removed??

I'm still stumped. I put new thermostats in today, and that didn't help a bit. When the engine water temp is bordering on overheating, the whole radiator is plum cold. I put a hose on the pad-cock on the bottom of the radiator to drain the coolant into jugs, and the first 4 gallons out were cold, then it turned so hot you couldn't hardly hold the hose for the rest of it. I've checked for restrictions in both the upper and lower radiator ports and hoses, and they seem fine. One thing that I have not done is to get coolant circulating through the heater core, because the temp control slide is stuck on cold position. Could that make an air-lock that won't give up until I have the heater core circulating, too? I really don't know what to check for next. It is possible that mice got a nest built in the engine somewhere, but I wouldn't know where. When I bought the engine, I thought everything opening was plugged, and I would hope that the guy who put the engine in took all of the plugs out! The thought of running it over a cliff has crossed my mind, But I couldn't do that to something orange. Hope there is some under-lying problem that I'll laugh about a year from now, Darrel

Check for a plug stuck inside the lower inlet side of water pump neck. Left a plug in a customers D-14 in my youth had the same symptoms as you describe. Those guys were really mad at me when they finally figured it out! Learned the hard way to always check holes for plugs.

MACK, I pulled one thermostat today, ran it for a good long time and it stayed well below normal operating temperature. Then I drained just enough coolant to put the thermostat back in, refilled the rad, and ran it again. Once again, the temp gauge was heading straight for the red zone. Any ideas what I should do next? Thanks, Darrel

If it ran cool with one thermostat out and hot with both in I would say it is not getting hot ( funkey gauge).

I have used a laser therometer to check the block temp and the radiator, and double check the temp gauge. Got one on sale at harbor freight, it's close enough to check for hot spots.

On my 8050, I had it split to fix some seals, when it came back the 4wd wouldn't go on.  The wire was off the shift solenoid on the side of the trans.  I was relieved!