Got hold of a blackbird injection fuel pump now and it fits inside the tank sat on a rubber seal. It has an external plug on it with 2 connections. My dad has worried me now by asking should it have any special circuitry connected to it to stop any potential sparks inside. Does anyone know whether this is the case on the bike loom or is it just a + and -? Also how much current do these things draw (fuse rating and wire size) and should the tank be earthed too? Thanks

Nope. No precautions needed (even if it does appear counter-intuitive).

there's nowhere near enough oxygen in a petrol tank to create a combustible mixture, never mind an explosive mixture.

it shouldn't spark anyway, but if it does, it could do it all day long and nothing would happen.

tom

i accidently wired my fuel level sensor to 12+ once buggered it up and all i got was a little puff of smoke.

Sounds scarier than it actually is then