Just been playing with the pump settings. Engine was a bit gutless on pick up but after sitting for 15 years I left it for a bit to see if there would be any problems.
On my diaphragm the dots seem to be in the wrong place compared to online ones.
I was wondering if the diaphragm plates have flats that lock onto the shaft or are they free to turn and locked by the nut only.
Turned the diaphragm 45 degrees clockwise and the old NA engine would have pulled better.
I have fitted it with max position right at the pin or front of pump.
I also moved star wheel 90 degrees but not too sure if it made any difference.
Now it is pulling like it should but wondering if max position is right, not seen any smoke.
I am thinking the normal 45 degree clockwise turn takes it to max position and dots just help to get there easier.
I marked everything to original setting but can see I am not the first in there.

Ignore the dot as you dont know whos been in there before, if you remove the whole pin and rubber and look at the tapered bit you will see the heaviest wear mark and thats where the pin will have spent most of its life, refit it with the wear mark 90 degrees clockwise from where it was originally fitted.
The main source of extra smoke/power is the max fuel screw mounted on the back of the pump body, if std will have a seal fitted, break the seal off with a screwdriver, loosen nut (13mm spanner) and wind the screw in (6mm spanner) , 6 and 13mm spanner to adjust, again 90 degrees in/clockwise and watch the thing go.

I never found star wheel made any noticeable difference