Hello,

thanks for the reply. I have just reconnected the gauges and it is producing a steady 3psi as it leaves the regulator and exactly the same pressure just before the first carb.

I have had it priming for about 4 minutes the engine off and it has maintained that pressure without leaking.

So, I am a little confused. The car has been stood for about 4 months so I suppose it is possible that the needle valve got stuck.