I have done everything I can think of to solve this problem-removed thermstat,replaced water pump,checked radiator caps,flushed water system,removed all hoses for inspection,installed temp guage,bled air from system,jumped fan to run constantly. This mule will circulate water just fine for some time then stops, have to bled system-pumps sometimes for couple hundred yards then same thing again. From cold start does good for maybe a mile if you are sure it is circulating then same thing again. Carb. heater was stoped up but have good flow now. HOPE SOMEONE CAN HELP ME ON THIS.