Carbs back on and first start up it ran and idled, ran like it had a fouled plug! Cleaned no 2 no change. Checked the fuel level it is at 27mm in the middle - I adjusted this on the bench using an old squeeze sauce bottle, gently squeezing to simulate 3lbs pressure which worked well!
Took some time to read and think things over then realised I had moved the carb sync screw during rebuild. Adjusted that and it is running pretty nicely, idling around 900rpm.
Now to tune the mixture and proper carb sync.
Update:
Had time to do the tuning, set mixture, using two gauge vacuum meters balance both ports in each carb and then then checked the carb to carb balance. Idling nicely around 900rpm and returning to idle after revving.
Test run, now revving sweetly and finally hits 6000 rpm.
Thanks to all who helped me on this post.