Chain saw needs to be primed

I have a very old Poulan inexpensive chainsaw. It has run faithfully for years. Last week I had to replace the fule line as the old one had deteriorated. I also replaced the fuel pick-up/filter in the tank.

Aftyer reassembling, I had a hard time getting it to pull fuel through the fiel line up to the carb. After priming with fuel directly into carb, it finally started and ran great. I left it for the balance of the day, and it now appears to have lost its prime again. What am I doing wrong. Did the factory pickup have a check valve, and perhaps my aftermarket replacement doesn't have one?

The Bob

 

The carb is probably not sealing completely and allowing the fuel to drain back into the tank. Or, if the fuel line is not a tight fit on the carb, it can drain back.

 

I'll pull the cover and make sure the hose is well sealed on the carb fitting. What else would be leaking inside the carb to allow the fuel to leak back?

 

Not sure exactly what carb you have, but a leaking diaphragm (hole in it or leaking around the edge where the cover should have it sealed), or possibly an inlet neelde not seating well could cause this.

 

Stupid ?, is the choke plate/primer working properly?

 

Is the stupid ?, stupid me or stupid you?