Thanks Bob, I took the carbys off and onto the bench, Checked all the levers and springs were assembled OK. I did the static setting of the butterfly valves very carefully this time and noted all valves were very uniform using the resistance of the paper strip as a guide after fine tuning the adjustments. Repeated this check three times!
I had done this on the initial carb assembly but did not appreciate how delicate this needs to be.
This was enough to fire the engine first start on no choke and she ran at 2,000 rpm . I hand pushed the throttle guide to close it some more and revs dropped initially about 1200 rpm and then to about 900rpm when the temp gauge was at working temp. Obviously should not have to do that.
Because it was idling so well, I then put the sync tool on and adjusted all within 2 cm/hg of each other I could hear the smoothness improving very nicely.
On my gauge the readings were 17-19 average and holding within 2cm/hg of each other.
So I now need to work out why the throttle is not just dropping back as the sync adjustment may be too tight and binding as you have suggested.
strata 6 ( Pete ) has made some good pointers also which is where it my problems seem to be .
Im not there yet but it was sure good to hear the motor purring at idle.
If you have had the 3 sync adjuster tubes completely stripped and rebuilt them, make sure all the springs and rods inside them are in the correct order and seated comfortably and correctly.
I always give them a light coating of grease before inserting them inside the tubes, just to be happy they are free moving and seated.
At the very bottom of each tube is a tiny steel "seat" which fits into the hole in the bottom of each tube. This sometimes does not always sit straight in the bottom of the tubes which will cause issues when you try to sync your carbs, as the adjustment will differ.
First of all in my message to Scotch I referred to my vacuum reading in cm/hg...it should read mm/hg.
With regard to the vacuum gauge mine is a 4 pot. I read elsewhere that only one vacuum port from each carby needs to be monitored its mate should be reading the same. You can move the rubber tubing over to the other port on each carby if you like if you suspect there may be an internal carby problem.