[BEB]

Thanks Guys;

Ist reply to Niles:
It is definitely a lean bog as I have a air/fuel analyser fitted in the form of a lambda sensor so I can see it momentarily leaning off.

To mr0077:
I may well have to go up 1 or 2 primary jets to compensate. Also, I have checked the accelerator pump arm gap at wide open throttle and it is .015". However, if the arm doesn't move immediately when opening the throttle does it mean I should try a different colour cam, and if so, which one as the current one is Green in the number 1 position.

To Rick:
I'm fairly certain the throttle plates are set correct (the primary one definitely is). The cam is a relatively mild Comp Cams 268 hydraulic and the idle vacuum is around 15/16Hg. The idle is nice and smooth.
I think the problem is caused by the accelerator pump not getting fuel in soon enough. I'm running a Green cam at the moment so which one will give a "faster delivery"?

Your feedback is excellent and I'm very grateful to you all !!!