I've been comparing parts in an 89 and a 276, and don't understand some differences.
The 89, which is 1 1/8" bore, has a longer needle jet and needle than the 276, which is only 1" bore.
Is the needle & jet longer because the carb is bigger so the slide has to raise farther, or do I have some weird parts?
Also, the needle jet isn't marked. Were they all the same size back in the 30's? The application is Matchless MX4, and the manuals
I have don't mention what the needle jet (or main jet) should be.
I checked the needle jet from my '55 Triumph, and it is marked, but the net in a 276/012 (not sure what it's from) isn't marked either.
Also, how do I check the float height? It's not adjustable, but I've got a dual float bowl, and the float valve seats hit the float needles at a different spot than the single floats I've got. I don't know if that's a sign that something's wrong or that the float valve is just a different diameter and at a different height.
Petrol is constantly dribbling out of the emulsion air holes on the side of the carb body, so I'm not sure if the float height is off, or maybe I'm supposed to have a long mixing chamber nut, or what.
Any clues will be appreciated.