fuel tank changed

[robygodzilla]

Having just changed the fuel tank on my 172 cup it's now not starting. I can hear the pump run briefly and I thought I'd maybe got the two lines plumbed in incorrectly but after lifting the rear seat and prising the pipe off nothing came out. I put just over 4 litres of petrol and was just wondering if this was enough for the pump to prime.

Any pointers before I go and put more petrol in and then realise I've got to drop the tank down again and give myself a nice little petrol shower.

Cheers
Robin