Checking for fuel leak.

[tonydeakin]

Following on from my last post, (see 'Almost an inferno' in general chat).
What is the best way to check for sticking carburettor floats etc without actually trying to start up? With the electric fuel pump and vacuum fuel tap on my 600 Diversion it does not attempt to drag the fuel through until the engine is turning over. As explained in previous post fuel leaked out and caught fire. As I'm sure you can imagine I am a little nervous of trying again even though I have had my fire extinguisher nicely re-charged.
Any (sensible) suggestions?
Tony

[bobh]

The "Prime" position on the fuel tap should allow petrol to flow without the need for a vacuum, so if you put it in that position and turn the ignition on - then stand well back, extinguisher at the ready ....