Priming JCB M25 strimmer?

Hi, my JCB strimmer priming bulb pump does not work, if I pull off the feed pipe to the carburetor and press the bulb the priming pump obviously works as fuel is pushed out of the pipe but it is not getting to the carb. Taking off the air cleaner and pouring a little petrol into the carb and it starts easily but does not draw fuel up from the tank.
I am assuming a blockage somewhere but having looked at the carb it seems to be non- servicable. Is this correct, if so where can I get a replacement?
Any ideas please
Keithg