I am working on a mtd snowblower with tecumsah 10 horse on it model lh358sa and when I prime the engine with starter fluid it keeps running fine. I shut the engine off and try to start it a few hours later it does not start on choke or by pressing the primer. I tried another carburetor on the machine which I cleaned and the same problem. The float bowl is filling up like iit should but no fuel is going in to the carburetor when I press the primer. I put a new primer and line on it also. When I get it running by priming the carburetor it idles and runs high speed fine. There is no needle valve under the float bowl just a nut with passages in the center and side which I made sure it was clean.