There are three versions of G23..The really old ones had points and small transfer ports, the next had slightly larger ports, and the last had a G62 style ignition with the small rotor and no points...The point gap on the older ones has a big effect on the timing, as it fires when the points open..If the gap is too large the timing gets retarded and really slows the engine down.Haven't run a points version for a few years, and forgot what the rpm was...We flew a 110 lb 16 foot wingspan Dornier seaplane a few years ago with 6 of the older ones, tried 15-8 props, wouldn't take off, changed to 14-10s and got it up that way...We tested the engines in the wind tunnel at ASU, showed about 11+ lbs thrust....
If you have a plane set up with a G23 a comparison with a G26 would be interesting..Come on up the hill someday and we can replace the G23 with my G26 for a test..We can fly at the Williams airport....A glow 23 weighs about 1 1/2 lbs, turns this prop about 8000....I made two from old parts, they both worked the same....