I have an RZT50 zero turn that will not start without a lot of cranking when it is cold or has been sitting at least overnite. If it is warm, it starts just fine. I can get by this situating by removing the air filter and giving it a shot of ether. It takes right off. Is this just my unit or are all cubs cold blooded. Btw, I have my old cub rider, a 1024 50", that has the same issue. Oh, both chokes do not kill the engine when fully on. Is this the problem?