I have a 5 hp tecumseh on a 22" yard machine snow thrower, the engine will only stay running if the primer bulb is continuously pressed or starting fluid is used

Remove the fuel line from the carburetor and check for fuel flow from the line--it should release a thin stream of fuel. If nothing or just drips, something is plugging the line, shut-off valve, fuel filter, or tank fitting. If fuel does run out, then the carburetor is not taking in fuel. Remove the carburetor from the engine--make notes of where the springs and rods go that operate the throttle. Remove the float bowl and the float needle--make sure the line connection is not plugged going to the needle valve. Check the jets for any plugging. Use spray carburetor cleaner to clean the interior. Hope this helps!