Ever notice on the GL1000 carburetor that small, stubby brass pipe sticking out on the air plenum side of the individual carburetor body? That's the float bowl vent. Yes, the float bowl vents through the air filter. Interesting. Here's another one. Everyone is familiar with the short rubber hoses that connect each carb body to the air plenum. What are they for? They're not fuel passages. And though they do carry air, guess what, it's not low pressure; it's not vacuum. It's atmospheric air (remove those hoses and absolutely no performance change will result). But atmospheric air to where? To the idle circuit. So each carb's idle circuit get its bleed air through the air filter too, just as the bowls do their vent air. Both are given atmospheric air that is filtered. Although these examples of convoluted carburetor air venting would become common on motorcycles in the early 1990s, it was rare on bikes in 1975. But not so rare on cars. Commonplace, in fact, due to emissions becoming a concern on cars some twenty years before it was on the bikes. And where did the first-generation Gold Wing carburetor originate? Yup, on a very early Honda car, the N600.