Much more likely that the short piece of rubber hose, which connects the nylon pipe to the tank unit, is perished.

That hose needs to be a good seal for fuel to be syphoned out of the tank and if it isn't, there will be problems with poor fuel delivery, worse when going uphill.

ken

you could try to blow in the fuel filler (make sure no air can escape there, so use a piece of tube and a cloth to seal it). if fuel still doenst run out well, there must be a leak somewhere/

Didn't I type a reply out here? That's not here now? I'm such a fucking tool.

Oh bollocks, right I'll check the seals again then Just want it to work now.

It is normal, so the pipe is most likely not blocked. Do you have different symptoms if the fuel tank is full, half full or near empty?
If so, it can be the little rubber tube connecting the fuel line and the sender unit in the tank. A guy I know, had at problem with his Mehari. When the tank was half full or less, he found that the problem was the suction tube in the sender unit, which had a little hole in it, caused by corrosion, which meant, that the pump was sucking air instead of petrol.