I have a Husqvarna 55 rancher that I seized up. I replaced the clyinder and piston and it starts right up while choked, but dies within a few seconds. If I manage to keep it running, it dies as soon as I open the throttle. The carb. was fine when I seized it, but I replaced it anyway with another one I had from the same model. But it still dies after a few seconds. I'v gone over everything a couple of times without any luck. Any thoughts?