Thanks again Bud.
Good info. I'll try to find someone who can do it for me without taking it in to a dealer.
I am getting a replacement radiator thermostat from Steve at Valley View Tractor & Equipment, Inc.
He was recommended to me by someone on this forum years ago and they have been great at getting and sending TYM Parts and also giving some advice. Apparently TYM have never sold an injector as a part. I'm just getting the radiator thermostat in case that is the problem although when it's billowing out gray smoke after running 10 mins the temp needle is in the middle