JETS AND EMULSION TUBES
There are three fuel circuits within the sidedraught — idle, pump and main — each of which have their own system of jets that can be altered to improve running, acceleration and the elimination of flat spots:
1. IDLE CIRCUIT
This isminute drillings strategically placed around the butterfly plate. It’s these holes that are uncovered when the carb begins to open and they promote the early introduction of fuel — eliminating stumble off-idle. Some engines need more than others — the Zetec for example has five, dictating a special series of 45 DCOE carburettor.