vacuum switch valve

I have a 1980 kz1000 shaft. The vacuum switch valve is missing on the valve covers. Is that switch important?

I've got a 79KZ 1000 and that valve caused my engine to run really rough and backfire etc.

I took it out, blocked off the two inlets on the valve covers and the bike runs waaaay better.

Bob

that is how my bike runs. I will try that tomorrow. I will let you know if that fixes my problem. Thanks

Just run a hose from one side to the other on the valve cover ports for a quick easy check.

If you'r bike backfires on decelleration and had the clean air system installed, look for a bad vacuum line.

do I need this or will the bike run fine without it?

No, You don't need that valve at all. Just junk it and plug the hoses going into the valve covers.

After you find out that the bike runs better without it, you can make a more permanent plug/repair. I made new plates to replace the ones that have a hose fitting built in. I made them out of aluminum plate.

Be sure to plug where the vacuum line used to go on the middle carb. That valve was vacuum operated.

Bob

thanks

The vacuum switch is needed to open the reed valves so that unburned crud can be dumped into the exhaust runner to burn for EPA purposes. If the valve isn't functioning (it works off engine vacuum), the system won't work... If you remove the vacuum switch, remove the hoses going from it and plug the two holes in the valve cover using BLACK PERMATEX RTV. Then keep in mind that ths vacuum switch was operated by vacuum coming from the carburetors. There will be vaccum hoses coming off 1 and 4 carburetors. These will go to a tee fitting and a single line from the tee will go to the vacuum switch. Remove all these hoses and buy 7/32" vacuum plugs and CAP the vacuum fittings on the #1 and #4 carbs. One of the other carbs (2) will have a hose going to the petcock but the last carb (#3) will already have a cap on the vacuum fitting. If any of the vacuum fittings are uncapped, the bike will race because these just make a giant air leak in the carb system. Last, there will be a hose from the crankcase breather to the emissions system. Remove this hose and put another hose on the breather that will hang over the swingarm. The crankcase breather is a vent and must not be plugged. Some folks put a filter on the thing but it isn't really necessary. I guess it might keep bugs out.

You can also tie Vacuum fittings 1 & 4 and 2 & 3 together.

If you remove all of the emission stuff, on the air filter side of the carbs there are 3 fittings. One big one is fuel inlet, and the two smaller ones are bowl vents, and shouldn't be capped off. If you are using pod filters, then these breathers should have lines running from them up and out of the way of any dirt. This is a good reason to "T" them to a little filter, so none of that gets inside the carbs.

thanks everybody for all the help....KG