hi again, the thermostat came out in pieces but it seems it was stuck closed because it was hard to open it even when the spring was missing. than i cranked it over when the housing was off and it pumped water out of it. i am assuming this means the water pump is pumping. I also foung that the radiator cap had no seal and was very loose and there was very little anti freeze in the rusty water.I will buy a new thermostat tmorrowand coolent and let you know i really appreciate you working with me. - thanks danny

because expanding gas absorbs heat from it's surrounding, the regulator needs warm engine coolant to keep it from freezing, when the coolant level is not getting to the regulator, but gas is flowing through it, it can freeze up.
there -may- be an LPG coolant line regulator, that slows or stops coolant flow if the coolant is too hot, but there is no other "sensor".

Thank you for your response i will be working on it again mon i will try the things you sugjested , why is the regulator freezing up, is there sensor if it gets to hot or something. the vaporizer and regulator are new. thanks a lot i really appreciate your help.

I am willing to bet you were really asking why it might do that, rather than just complaining about it. you either have no coolant in the engine block and/or a stuck thermostat maybe a broken impeller on the water pump or missing water pump belt.
I would also bet you have an LPG powered machine and are freezing up the regulator, and that is what explains the shut down that may have prevented further damage to the engine.
But it might be the headgasket is blown.
check all fluid levels and check the radiator's flow.