accelerator pumps?

Would someone be so kind, and explain to me the purpose of the accelerator pump on my carbs? Also, how does it work? Is it necessary for my carbs to operate properly? What would happen if I just ripped it off? I know my previous KZ650 had very similar carbs that did not have an accelerator pump. Thanks very much! :laugh:

I have one on my carbs too. I have no idea what it's for, bit I'm very much looking forward to the answer!

Accelerator pumps are for accelerating. When you goose the throttle it injects more fuel into your intake for a lag free rapid acceleration. It only pumps when you give it throttle, so its not something that's bogging your engine down.
I would advise leaving them on.

.

Kawasaki installed accelerator pumps in 79 and 80 as one of the ways to work around EPA emissions standards.

The EPA tests the exhaust gases with the bike running - but not when they are accelerating - so by leaning the jetting on the mid range (coupled with the infamous reed valves) Kawasaki was able to keep the bikes under the standard. When you ride, the accelerator pump helps make up for a very lean lower mid-range and boosts the fuel for a second or two.

The way the pump works:
On the bell-crank / cable pulley, there's a rod that pushes on a diaphragm under one of the inner carb bodies - that diaphragm pushes fuel out through each carb through some small diameter hose into a nozzle that squirts the raw fuel down the throat of each carb.

Coupled with the accelerator pump are those reed valves over the exhaust cam. These are another way Kawasaki worked around the emissions standard. The EPA standard only stipulated PPM of the gases - so the ingenious folks at Kawasaki devised a way of adding air to the exhaust gases to dilute the PPM. It didn't change the amount of pulutants - just the ratio of them... sneaky huh...

I didn't know what exactly it was for, but I knew I liked having it on there for some reason!

Wow, interesting, thanks! I really dislike those features, and i really really dislike the EPA. So judging by your explination, am I correct to assume that the older carbs that dont have accelerator pumps were better? I am planning on getting a new set of carbs eventually, as well as capping off that air recirculation system. I havent been able to find any of those block off plates specifically for a KZ650. Do you think I can just swap valve covers with an older motor?

The 77-78 carbs are a better chioce - if only for the fact they have adjustable needles. The 79-80 version only have 1 clip setting.