Does the brass part in middle of Air Cut Valve move ?

[aSTerix]

I read somewhere that the brass part in middle of the Air Cut Valve is meant to move, mine (on all 4 carbs) is rock solid.

Just wanted to check whether it should move or not ?

If it is meant to move then any suggestions how to get it unstuck

 

[Slydynbye]

The little diaphragm has a metal piece in the center that should move in and out of that hole.

 

[jrp]

The brass part in the middle does not move. It is not stuck.

 

[afrymoyer]

There is a spring loaded plunger in the center. It must be freed up to allow air from the vacuum piston chamber into the slow speed/pilot circuit. I bet it's varnished badly. You can get at both sides of the plunger. One side with the air cut cover removed, and the other with the big vacuum piston diaphragm cover and slider removed. Spray both sides with carb cleaner and try pushing in on the plunger with a pick to free it up. If it won't move, let it soak for a while and keep trying.

 

[jrp]

There is a spring loaded plunger in the center. It must be freed up to allow air from the vacuum piston chamber into the slow speed/pilot circuit. I bet it's varnished badly. You can get at both sides of the plunger. One side with the air cut cover removed, and the other with the big vacuum piston diaphragm cover and slider removed. Spray both sides with carb cleaner and try pushing in on the plunger with a pick to free it up. If it won't move, let it soak for a while and keep trying.

I obviously did not know this. I will have to take another look at mine.

 

[aSTerix]

There is a spring loaded plunger in the center. It must be freed up to allow air from the vacuum piston chamber into the slow speed/pilot circuit. I bet it's varnished badly. You can get at both sides of the plunger. One side with the air cut cover removed, and the other with the big vacuum piston diaphragm cover and slider removed. Spray both sides with carb cleaner and try pushing in on the plunger with a pick to free it up. If it won't move, let it soak for a while and keep trying.

Thanks for tip about the access via the diaphragm chamber, that allowed me to get the carb cleaner directly where it needed to go , all are moving now