Carburetor and engine vacuum system question b1

OK i ran into a huge problem i believe. i have a 78 kz400 b1. I want to put cone filters on my dual carbs. Problem is, i believe the vacuum hose on top of the angine connects to the air box and routes to the top of the carburetor intake hole in order to push air into the diaphragm which lifts the slide......Is this true? if so, is ther any easy way to put those cone filters on and get it to run??? can i just block off the vacuum???? idk at this point. I see people with b1s who have megaphone or cone filters on but idk how they did it!!

gumby prichard wrote: OK i ran into a huge problem i believe. i have a 78 kz400 b1. I want to put cone filters on my dual carbs. Problem is, i believe the vacuum hose on top of the angine connects to the air box and routes to the top of the carburetor intake hole in order to push air into the diaphragm which lifts the slide......Is this true?

Not true. The big hose is just crankcase ventilation. You can just put a filter on it, or just run a big hose down to the ground, but don't let it get kinked.

gumby prichard wrote: is ther any easy way to put those cone filters on and get it to run???

Not without a lot of playing around with jetting.

gumby prichard wrote: I see people with b1s who have megaphone or cone filters on but idk how they did it!!

Some are just riding it not running correctly, and some have taken the time to rejet the carbs.

your so much help thanks! any links to threads that might lead me too the proper jet sizes?

Sorry. I've only done it on the older piston-slide Keihins, not the diaphragm ones.
Someone on the twins forum might be able to help, or at least might have some decent links.
If you really like fabricating custom stuff, you may want to look into making a 2-into-1 manifold and running a single, simpler carb. A few members on the twins forum have done that too, and it looks trick.

KZ400 twins forum

already did it!!!! lol but i want to switch because it doesnt make a very healthy sound.