[Mick Barratt]

'Fraid you're mixing up two things here! The tickler just holds the float down mechanically, which forcess the float needle to open all the way and flood the carb. So if it's slow, then something is blocked in the fuel feed, possibly at the tap filter, but easy enough to find by just by loosening connections from the tank downwards to find the blockage.
The pilot air screw is only meant for setting the idle smoothly once the engine is running and up to temperature, NOT for starting. What you have done is make the idle far too rich by cutting off the idle air passage, no wonder it is lumpy screwed all the way in.
You don't say if you have a choke fitted, but as you live in our somewhat cooler climate, you should probably have one for starting and initial running, certainly this time of year. However, the engine should at least start easily with a fully flooded carb, even without a choke, so I suggest starting with the fuel flow problem and go from there,
HTH

 

[Mick Barratt]

This was the case with a bike I was working on recently. The fuel level was set so low it took ages to tickle. Eventually it would flood and start , idle poorly and then die and be difficult to start again. Setting the float correctly sorted it completed.

Sorry, the float level has NO effect on the tickling, if the float is held down by the tickler, the fuel will flood - period, as long as fuel is not blocked. How the bike will run after starting with the wrong fuel level is another matter.
PS if the fuel level is VERY low (never seen that with Premiers), then it will take a little longer to fill, by only with poor flow.

 

[Mick Barratt]

No, the float was so far down the tickler barely reached to push it down, hence the valve wasn’t fully open and it took a long time to tickle.

Fair enough, but never seen that on a Premier. 'Spose if someone had messed with it.....

 

[Mick Barratt]

I guess I've just been lucky, I've had 3 sets of Premiers in the fairly recent past (and a set of Wassels, less said the better) and they were dead right out of the box.