Gents

Maybe interesting for if you can find one.
The carburetor of the old OPS RC 60 in detail. (Same for 40)
1 Main fuel needle (valve)
2 Second needle
3 Air bleed screw
4 Limit screw for barrel position in idle position.

Adjustment is more complicated but there is a better, more independent, adjustment possible for fuel/air ratio in midrange with needle 2.
Best fuel/air ratio adjustment for idle position has to be done with the bleed airscrew.
RPM idle adjustment stop (if you want to use it) can be done with 4

The OPS engine with the pipe (pitstop000, post 9) seems to have a fixed venturi!



Cees