2 must have something connected or the slides will remain shut? :s

they will open as the revs rise.

there variable choke carbs, the butterfly controls throttle, while the slides control the airflow and fuelling.

just to check, what bike are they off? I'm assuming there CBR's but what year/model bike?

EDIT: There is a possiblity that they came off a bike that used a RAMAIR style induction system so that would have been plumbed into the airbox, the rising pressure of air forced into the box as you accelerate would allow the slides to open faster giving better high speed throttle response.

Edited 15 July, 201115 yr by Cymro

As cheys say's, the sliders are opened from the pressure differential.

They have the needles built into them slides...I don't believe they'd open themselves..there's resistance on them, it's like it needs something connected to move them, surely that connections there for a reason?

They are off a cbr 600, have no idea which though, they don't have a throttle position sensor or anything though

Blow hard down the choke and see what happens.

or suck from other end

i dont see how blowing air/sucking on a flat face would make it slide upwards? blowing on the pipe connection slides them up. so surely something needs to be connected relavent to engine speed? :s

i dont see how blowing air/sucking on a flat face would make it slide upwards? blowing on the pipe connection slides them up. so surely something needs to be connected relavent to engine speed? :s

god knows haha , I'm gonna slap em on and hope for the best haha !

Manifold looks nice

Manifold looks nice

Thanks :)

use a hover, get a mate to hold the carbs, place the nozzle close to the butterfly side, open the throttle butterfly to full throttle, move the nozzle closer or further and the slides will move upwards and downwards in relation to the amount of vacuum flowing through them.

The only other answer I can give is that its a pitot tube connection for a turbo bike.

Edited 16 July, 201115 yr by Cymro

its not that i dont believe you or anything lol..its just the fact its clearly a connection for a pipe so should be used for something? like crankcase breather?

So I was just reading this...which does make sense to whats been said about it will open itself etc..its just hard to believe feeling the resistance on the spring. I just want to know what the pipe connection would go to :S maybe its not necessary on the car fitment but do I blank it or put a filter on or what?

http://www.omnilex.com/public/bmw78/cvcarb.pdf

also, the spring which people say they chop coils off, is this the spring which forces the choke slide back down...eg a lot less revs than a bike means the slide wont fully open, therefore less spring resistance means at full rpm carb slide will be open fully, as apposed to like half way to what it would be on a bike? obviously this is rough due to the CC difference etc...but you get the idea!