|Looking from the engine manifold, half throttle|
|Splatter plate to help vapourise the fuel, since the air flow is concentric with the main jet not
perpendicular with it.
looking deeper past the splatter tube, the casting is threaded to take a venturi insert, we think.
Anybody any ideas for main jet size or venturi restriction ratio?
|Zenith carburettor from period with many similar design features. On right, same diagram but colour coded by me.
Blue is main fuel feed to main jet
Mauve is auxiliary for medium speed running
Green is slow speed running
Yellow is venturi