If the primer bulb is stuck in that means there is either a kink in the fuel line or the screen inside the carb is full of trash.Easy fix, just remove the four screws that hold the top cover on the carb, that will be the side where the fuel inlet goes into the carb. Remove the cover and pay close attention to the orientation of the diaphragms. you will then see a small round hole that is probably packed tight with Osage saw dust, there is a small fine mesh screen in that hole, take an ice pick and pop it out. Clean screen and reassemble. If you are going to replace the fuel lines, I would also replace the primer bulb. I have been a chain saw mechanic for over thirty years, PM me if you need any help. Dan