new motor to me...2005... 5 - 7 min idle with muffs and the overheat indicator goes on (red) with solid alarm...20 sec later shuts off (normal procedure. checked thermostats and clear and working (have not hot water tested yet) 150f and 160f) What is the next logical step? Pull the impellor? (there is a stream although not as strong i've seen with other engines I've owned) I'm at a loss what direction (time and $$$) to procedure on....