I have a Huskee mower with a Techumseh OHV 13 that will only start on gas or starting fluid being sprayed into the carb. Runs fine after that until the next the next time I go to use it. I have taken the carb apart which was clean. Check fuel flow from filter which was good. Check choke adjustment which is good. Has plenty of spark. It is a Techumseh OHV 13 206801A (H) DOM 7/10. Any Ideas ??