I have an old blower. The prime bulb will not fill up with fuel. I bought a new carb but it did not come with a pribe bulb on it, it had a plate where the prime bulb goes. I put the old prime bulb on the new carb and I have the same issue. I replaced the fuel lines but not the filter at the end of the fuel line. Do you know if this filter is suppose to be a filter/check valve? As I press/depress the prime bulb I can see fuel going up the tube but then back down. It almost seems like it needs a check valve to keep the fuel from going back in the tank. The fuel never fills the bulb. Any suggestions would be appreciated.