I can´t get the best RPM with a Propeller 12.25 x 3.75. I am using a Mini Pipe.
First of all I discovered, that the spring of the low needle did not adjust very well, so, I replaced for a new one.
Now I have two questions:

1.- How many turns need the low needle, because the manual said 1.2 mm
2.- How separate should be the Pipe from the tube ? Some said 1/2 inches. some said 2mm