Carburettor Terminology

Hi all In the workshop manual under the technical specs section for Carbs there are two references to "Mute" ????
The first is for main jet 230; 220 with Mute
The second is for needle position top with Mute

Now mute to me says some sort of baffle of restriction, which with the main jet i could see (even if i don't quite get). But what this refers to with the needle position i haven't a clue

Any ideas what put my mind at test

olympus said:

Now mute to me says some sort of baffle of restriction,

Click to expand...

The mute is item 34.
https://andover-norton.co.uk/en/shop-drawing/46/exhausts-mufflers-mute-passenger-footpegs

Silencer mute, got it. Thanks Les

Ah, i see, its the carb jet/needle recommendations if you are running silencers with mutes.

The needle jet size should be such that lowering the needle causes a miss. Then the needle jet size is within the adjustment range of the notches on the needle. Any change to exhaust system, compression ratio or ignition advance usually requires moving the needle up or down. The taper on the needle affects how quickly the throttle can be opened. Lean jetting usually gives better performance, but a slow taper needle requires more control in opening the throttle. It is counter-intuitive - more speed should probably be achieved by whacking the throttle open - but a more moderate approach is usually better. When two-strokes arrived, many of us did not know the throttle must be fed-on - not whacked open. It is probably the reason two-strokes were faster than four-strokes of similar capacity. A two-stroke which is jetted rich will often not even start.

I think two strokes are more powerful than four strokes because the power stroke is every revolution instead of every second revolution.
Dennis