Removal of stock airbox and parts related

ok ... got my carb issues worked out, and jetting resolved. My next questions is this.

Can the vacuum switch and related hoses and such be removed from my bike? If so, should the Reed valve caps on the cylinder head cover be replaced/capped? I have noticed that the parts diagram only lists it for US models, I assume its emissions related, but I want to remove it all as it just isn't functional anymore, or so i believe. Here is a pic of what i want to remove.



The stock airbox is already gone, and the hose labeled as 26 just goes to the open air above the carbs. The hoses labeled as 24 go to the vacuum nipples on carbs 1 and 4.

I want to pull it all and just cap the nipples on all carbs. Will this be beneficial to me or just cause more problems?

Zephyus wrote:

Can the vacuum switch and related hoses and such be removed from my bike?

Your setup looks very similar to what my KZ1000 had and it has been removed. The hoses from the valve cover sides are just spliced together and the carb vent lines remain open to atmosphere.(I ran mine down under the bike) Everything else is removed.

Sonny

Ahhh Sonny? The vent lines have nothing to do with this system... The vacuum ports on all four carbs need to be capped using vacuum caps. You can also either connect the reed valve ports on the valve cover with a hose OR plug the ports with black RTV (silicon stuff) OR you can tap the ports and install threaded plugs but the ports must not be left open.

wiredgeorge wrote:

Ahhh Sonny? The vent lines have nothing to do with this system... The vacuum ports on all four carbs need to be capped using vacuum caps.

Would it be better to tie them all together in parallel to make an equalizer tube kind of setup?

I didn't mention anything about vent lines in this system. I understand that the two tubes coming from the carb vacuum nipples connect to a tee and then to the vacuum switch that controls the reed valves in the top of the cylinder head cover. This system is just a vacuum operated switch that controls the reed valves on the top of the cylinder head cover. It allows fresh air to enter the exhaust chamber to prevent backfiring on deceleration, or at least that is what my Clymer says it is.

Judging from your response, George, I am assuming it is safe to remove this entire system and plug the nipples on 1 and 4, and plug the reed valves on the top of the cylinder head cover?

Is there a similar cover on foreign bikes of this model that do not have the reed valves, but instead just a solid cover?

Zephyus wrote:

I didn't mention anything about vent lines in this system.

Whoops!....Sorry, I shouldn't be answering posts while I'm (supposed to be) at work!

Your system ISN'T like mine after all.

Please disregard...I'm glad some vigilant folks were looking on. I'll pay more attention in the future.

Sonny

No problem. There are vacuum fittings on the carb holders on the 81 model I think. Remove the vacuum lines that connect to the emissions junk. Remove the vacuum switch. remove the lines that went to the airbox. You will be left with two open ports on the valve cover. This system works the same for virtually all motorcycles. My 2001 Bandit 1200S had the same system. Anyway, you have options as to what to do with the valve cover. First, if you find a foreign spec valve cover, the cylinder head may not have been designed to accommodate a reed valve system so may not be shaped to cover the runners coming from just outside the combustion chamber up to the reed valves. These runners sit in the exhaust ports so if the bike backfires, flames could follow the runners and you might have open flames under your gas tank. It is important to cover these runners. Anyway, ON SOME KAW MODELS, the foreign spec valve covers do cover the runners but I can't say if they do for yours as there is no parts diagrams to refer to.

OK... if you leave your valve cover on, on KZ900/1000 models, APE sells a very attactive block off plate. You must keep the actual reed valves as they gasket the opening so the solution you choose will involve keep the reed valves which just sit in the valve cover opening once the top is taken off. If the 900/1000 covers don't work for your bike, you can plug the ports on the covers in a variety of ways. I just fill them in with black RTV. Some folks have threaded the inside of the ports and screwed in a large bolt. Others connect the two ports with a hose.

You really don't need to plug the hole in the airbox but you can if you like. It won't change airflow and air coming through the small hole will still get filtered.