kz550 ltd c vacuum switch

hello all. thanks for all the beneficial information that you have provided here. this is a first post, so bear with me. Ive pulled the vacuum valve and hoses off and also caped all the ports. My question is..... do i just need to re-sync the carbs or do i need this ugly hose stuff? I have seen a thread where it was suggested to remove this. just wondering. 1981 kz550 ltd c

If you are referring to the Clean Air System, then all you need to do is cap everything off and ride.

Be sure to retain the vacuum line to the petcock and all the carburetor vent or overflow hoses. They are not part of the CAS, and you need them.

The only way it might affect the carb sync is if the system was leaking and a previous owner had to compensate for the leak. Then capping everything off might require a re-sync. But you will know right away. When you pull the stuff off and cap everything tight, the bike should not run any different. If it does, (and it runs worse, not better) then you may want to look into re-syncing.

i believe what you described is exactly what the PO had done. Any tips at all on capping, just to ensure tightness and safety?

If you replace the valve cover ports with block-off plates. make sure to leave the reed-valve frame in place. They have the rubber seal which seals the plate. In fact, it's pretty easy to break the frame if you try to pull it out. Leave it in.

The easiest way to cap the valve cover is to just connect the two ports with a hose.

The port in the airbox, if you have an airbox, is easy to plug with any rubber cork-like object. Automotive stores will sell large vacuum caps that will fit into the hole just like a cork.

The vacuum pipes on the intake manifolds are trickier. The vacuum caps sold at parts stores won't last long in contact with gasoline/alcohol vapor. I use short bits of high-quality, rubber, automotive fuel line on them, and then plug the end with a stainless steel allen screw head (find some smooth ones). Obviously you can use anything that will plug the hose, but make sure it won't fit into the vacuum pipe.