® Air bleed tech

As I used to drum into my tech students, every atomizing circuit in a carburetor has an air bleed. (The qualification of "atomizing" accounted for accelerator pump and similar non-atomizing circuits whose fuel is atomized after discharge into the venturi and not before as is true of all the carb's metered circuits).

An air bleed is simply one of the three legs of each fuel discharge circuit. One leg is the fuel, another is the air -- that's the air bleed -- and the third is the atomized air and fuel together at the curcuit's outlet into the venturi. Pre-atomization you could call this. Makes for improved air and fuel homogenization in the combustion chamber, with the result a more complete burn and even enhanced throttle response and torque.

A rather unintuitive thing about air bleeds is the fact that Japanese carburetor manufacturers frequently put the smallest one on the larger, main jet circuit and the larger one on the smaller, idle curcuit. Those experienced in tuning racing carburetors can tell us why air bleeds might work better that way, as their work includes manipulating the air bleeds to gain effects that are achievable no other way. The rest of us will simply marvel at it all.

All of this meets the practical when, in the case of the GL1000, you have no less than 12 removable air bleed jets to get into their proper places during a carburetor rebuild.

Last updated September 2021
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