Looking to learn

Gents. I would like to better understand Kaw's (for lack of better term) AIR system. It seems, that there is an exhaust passage aft of head gasket to valve cover. which pairs cyls 1-2 and 3-4 within valve cover. which meet with paired flapper valves.logic indicates these open with exhaust pulses. The vented side of these chambers usually go to a vacumn uperated (GULP) valve which allows fresh air access from airbox to these flappers under accelleration(high vacumn at carb intake throats) again by guess, this fresh air would promote burning of unspent exaust. thus cleaning end product. If my surmises are correct, wouldn't the easiest/way to dis-able system be to simply to issure flapper valves can not open? The vacumn which operate'ed the Gulp valve (usually tee'd lines from #1&4 carbs)should be blocked from atmosphere, But I'm unsure as to whether optimum would be to block at carb bodies, or to "T" the three vacumn sourses (1-2-4 together and send to vacumn petcock as a gang. Yamaha's YICS system tied all 4 cyls intake vac's together as a single passage inside a head passage, and many current FI bikes join intake vacumns externally. Like I said, I'm eager to learn, and welcome views/info.G

A few years ago I scanned a page from an old magazine that was a Kawasaki ad that described the air injection system. I know it is on the computer at work but I can't find it here at home.

As I understand the Kawasaki system as it was sold in 1979 is that the vacuum switch shuts off the flow of fresh air to the exhaust system under deceleration (heavy vacuum when the slides are closed). One of the signs of a failing vacuum switch is popping from the exhaust on deceleration. The Kawasaki system is quite simple.

Here is the ad that I referred to:

Nonb, Thanks, I guess I booted another one. appreciate being set straight. G

Huh, I always thought that those passages were crankcase breathers like a PCV on a car. I'm glad I know better now

The breather on the 650/750 engines is in the middle of the transmission just in front of the airbox. A 90 degree rubber tube connects it to a nipple on the airbox. When a conversion is done to pods, most usually install a small filter on that pipe of the breather unit.

Actually Kawasaki did provide an elegant solution to cleaning up emission with the air injection system as it did the job with minimal weight and parts, as least as minimal as could probably be expected. I'm unfamiliar with how the other manufacturers tackled the problem, but by using this system on the 650s, they were able to utilize accelerator pumps and, IMO, actually gained performance while meeting the emissions laws.

When the vacuum switch goes bad, the easy way to "fix" the problem is to run a hose between the two ports in the valve cover, remove the switch, plug the hole in the airbox and remove and plug the nipples on the intake boots where the switch lines connected.

Detailed view...