Teikei carb settings for my Nordy

[Chichor]

Hi everybody, this is chichor form Spain and I'm new here. I hope someone can help me and my Nordwest. Recently I have bought this incredible curve machine, but I'm having problems with the original Teikei carb since it is not well adjusted indeed.
And these are the symptoms:
1- Impossible to start the engine with the starter pulled on.
(without using the starter, the engine starts quiet well if I help it a little bit with the throttle)
2- Since I can not use the starter to warm the engine, it's very difficult to keep a uniform idle until the engine gets quite warm.
3- When I'm warming the engine (Throttle blows) before ride the bike, the engine rpm returns to the idle rpm more slowly than normal (some times do not return to idle for a while)
4- From about 3500-4000 rpm to full open throttle the engine runs really smoothly and powerful, but under 3500-4000 rpm the engine runs a bit unstable (not smoothly) for example when I'm riding behind a slow car

And this is my problem. (Air filter is OK, spark is OK, carb float level is OK, jets are OK)
Has anybody an idea about what's going on with my carb?

Two more things:
The workshop manual said that the Air screw must be turn out 1,5 turns (+/- 0,5) but other info in internet says, 3 turns (+/- 0,5) ...which is the correct setting?
And lastly, concerning to the secondary (vacum) carb synchronization, does anybody know how many mm should I raise the primary carb throttle valve to adjust the synchronizing screw in order to get that the secondary throttle shaft contacts the secondary throttle push lever??

Many thanks in advance to all of you !!! Finally I gotta Gilera Nordy!