If I understand what you mean: with the octave key pressed, the G key (which covers the A tonehole) doesn't open smoothly when you release it to go from octave G to octave A.
If this is what you mean, then:
With the neck off, finger octave G (123 ok). With your right hand, move the octave lever to and away from the body. Does it move easily with NO friction whatsoever? If no, you've got binding somewhere in your octave mechanism. Its a complicated mechanism and there are literally dozens of reasons it could be happening, so I'd say try to figure it out yourself by isolating moving parts or just take it to a tech.
If yes, then finger octave G (neck still off) holding the octave actuating lever against the body lightly with your right hand. Then slowly release the G key to finger octave A., keeping the body octave lever pressed to the body with your right thumb. Does the motion of the G key pressing down on the body octave key smoothly translate into force pushing outwards on your right thumb, pushing the body octave lever open? If you release the octave lever with your right hand does the G open up quickly just like any other key, and the body octave pad closes while the body octave lever opens quickly and smoothly? If no, you've got friction between your G key and your body octave key, probably due to a poor material choice or damaged adjustment material on the G key foot. If yes...
Attach the neck and repeat the A-G test. Is everything completely smooth, no problems? If yes, your problem has disappeared. If no, probably there is friction between your neck octave key and the octave actuating lever on the body- probably as a result of a bad material choice for the actuating lever.
If none of this works, let us know what you find.
(edit: as Stephen says below {good call!}, your G spring could also be too weak. )
If this is what you mean, then:
With the neck off, finger octave G (123 ok). With your right hand, move the octave lever to and away from the body. Does it move easily with NO friction whatsoever? If no, you've got binding somewhere in your octave mechanism. Its a complicated mechanism and there are literally dozens of reasons it could be happening, so I'd say try to figure it out yourself by isolating moving parts or just take it to a tech.
If yes, then finger octave G (neck still off) holding the octave actuating lever against the body lightly with your right hand. Then slowly release the G key to finger octave A., keeping the body octave lever pressed to the body with your right thumb. Does the motion of the G key pressing down on the body octave key smoothly translate into force pushing outwards on your right thumb, pushing the body octave lever open? If you release the octave lever with your right hand does the G open up quickly just like any other key, and the body octave pad closes while the body octave lever opens quickly and smoothly? If no, you've got friction between your G key and your body octave key, probably due to a poor material choice or damaged adjustment material on the G key foot. If yes...
Attach the neck and repeat the A-G test. Is everything completely smooth, no problems? If yes, your problem has disappeared. If no, probably there is friction between your neck octave key and the octave actuating lever on the body- probably as a result of a bad material choice for the actuating lever.
If none of this works, let us know what you find.
(edit: as Stephen says below {good call!}, your G spring could also be too weak. )
