I have tried every possible thing I can think of: new spark plug, checked compression, replaced all gas lines, replaced primer bulb, disassembled and cleaned carb, changed gas. Saw will start, but it will only burn the gas from the primer bulb. Throttle works fine, and I can keep the saw going if I gently keep pumping the primer bulb. As soon as I stop, the saw stalls out. Obviously the carb is not pulling the gas from the bulb, but I dont know what else to do.