RE: Saito FG-20 or 21
Bill at C&H would have to change the pickup position or install his timing ring .
The Saito ignition pickup is at Top Dead Center and the ignition retards timing for startup .
The C&H ignition pickup is retarded 22 degrees or so for startup and idle and then advances the
timing for run .
That is my understanding , could be wrong .
But if I am right it is a shame that there could not have been a standard way of doing it .
RC foolish is correct
We used to solder a tube to the vent hole but we used to run the tube inside the fuselage
and the reason being to keep the prop wash from changing the pressure that the regulator
sees .