Overheating RX-7

I have recently purchased a repossesed 1987 Generation 2 RX-7. stock as far as I can tell. (N/A) Got a nice deal on it. The Battery in it was dead, so I jumped it. And got it started up and it ran for 5 minutes or so got it up to 50 so there aren't any drive train problems. Only thing is that once it stopped we couldn't get it to start up again.
tried a little starting fluid to no avail. We towed it back to the shop and later got it to start up again, but we were just letting it idle a little bit to see how it was going. It wouldn't idle on its own, but rather would have died. Then the heat gauge shot up to almost all the way on the engine. Just from idling around 1,500 rpm. So we killed the engine and let it go. We haven't been able to get it started back up since.
One of my friends thinks the thermostat has gone bad on it and suggests that we just take out the thermostat entirely.

I am just looking for some help on what I should do to figure what is the correct problem, and what to do to get it fixed. Any input would be appriciated.

sell it to me for parts....hahaha,
but really remove the thermostat and put it in a coffie can with water.
heat it up with a torch. if it opens its good. if it dont its bad.but if the motor is bad than sell it to me for parts...
later and good luck

Thanks, I will defenitely have to try that. Anyone else run into such problems? Anyone want to take this one off my hands for $1800? I am in Utah near Salt Lake City.

I am just looking for some help on what I should do to figure what is the correct problem, and what to do to get it fixed. Any input would be appriciated.
FWIW, rotaries are VERY sensitive to overheating. Whatever caused the problem initially you may very well have another BIG one! Overheating generally melts the apex seals, which = "total rebuild". The easiest way I know to find out if that happened is to have a compression check done. You (or your mechanic) must have a rotary compression tester. A "normal" compression kit will not work!

A very UNscientific way to do it is to remove the Trailing (top) plugs one-at-a-time, hold your hand over the hole and have someone turn the engine over. There are 3 seals per rotor, so you will generally get "strong-strong-weak, strong-strong-weak", or "strong-weak-weak, strong-weak-weak" , etc. The "weak" ones are bad seals. The problem is, it's hard to tell (without experience) "strong-strong-strong" from "weak-weak-weak".

Even if 1 seal is bad, the engine will likely have to be rebuilt. At that point it makes sense to replace all 6.

Before you go starting that new engine, make sure your cooling system is OK. There's only 1 thing worse than overheating a rotary. That's overheating the rebuilt one as soon as you put it in :banghead: .

Good luck!

Ok Well I tried what was suggested on someone elses thread, that of towing the car until it gets its engine going. That worked. And we were able to get it going along and were able to take it out on the freeway and get up to 90 mph. So its going well enough, Just smokes a little and doesn't idle currently. I think it would even start up well right now if we got a new battery into it. I think my friend may have misread the heat guage since it is doing ok at this point...
The engine does run a bit rough, we are going to try cleaning out /replacing the fuel injectors and see if that helps much,