Anything and everything Spitfire.

My car is running too lean at the top of its rev range. It runs well below 4250rpm but will not push above 4500rpm without me pulling the choke out once I hit about 4000!

I have a club standard exhaust rear section fitted and pancake air filters (not K+N's). The standard needles recommended for this engine are AN and those are what's currently fitted.

I wonder whether anyone out there has any experience of these engines and this symptom. There seems to be no previous mention of the 1147cc engine with this issue on the message board.

Any suggestions much appreciated. Also, if necessary, any good rolling road/tuning specialists around Gloucestershire who could sort this out by trial and error?

Tarquin