Steve, not sure what a #4 slide is, is that 4mm cutaway? if so you could try it and maybe up the pilot to 40 or 45 and screw the air screw in a bit. The more the cutaway the more tendancy to run a little pingy lean on small throttle openings with high revs like when you are just feathering the throttle. The setup i have is just on the rich side of a ping at very small throttle openings but the main advantage is the huge improvement in throttle response, if the throttle is blipped she has an instant rev. With the old 2mm or 2,5mm slides the revs tend to build slower. The V force reeds are a must too, they are great. The powerband i have now is nice and smooth. Oh i also run BP race fuel 100 leaded.
