Interesting, I didn't realise that the pick up pipe was down inside the well within the drain plug. This well was full of gunge and the pipe pressed hard against the plug because the bottom of the tank is fairly well stove in (to use a nautical term).

Anyway, petrol flows for now and when the weather is warmer I'll drop the tank and clean it properly.

I don't know wether this helps.

I have avoided this scenario by keeping the tank full of petrol in the winter and putting half a bottle of Millers "Tank Safe" in.
No Rust is the result !

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