Carbs velocity stacks

[solidstateirons]

hello, i recently heard some friends talk about velocity stacks and i found on the net that they make them for xs650 carbs. Can anybody explain to me what is the difference between them and regular filters?

Thanks in advance!

 

[Royboy]

True velocity stacks offer no air filtration. Might be OK for a drag bike but not something I would do to my daily rider.

roy

 

[mrtwowheel]

velocity stacks = remove sparkplug, insert dirt

 

[solidstateirons]

So in other words, makes the bike "faster" cause of the air intake but not safe to the engine's life.

 

[grizld1]

You'll shorten engine life with velocity stacks, but you won't make the bike faster. Vacuum carburetors (that's all OE carbs on all XS650 models) use the difference between low pressure above the slide diaphragm and atmospheric pressure below it to lift the slide. Air currents moving across the back of the intake bell can lower air pressure at the port that vents the lower diaphragm chamber. That's why all manufacturers use a still air box with vacuum carburetors, even on balls-to-the-wall performance machines. You won't gain power by hanging velocity stacks on OE XS650 carburetors, you'll lose it.

 

[joebgd]

What does the BS and the CV stand for on our oem carbs? I'm guessing the V in the CV is vacuum.

 

[azman857]

CV=Constant Velocity
BS= Series of carbs used by many motorcycles

 

[grizld1]

CV=Constant Velocity, which was Keihin's designation for their first series of OE diaphragm slide motorcycle carburetors, but often used as a generic term for diaphragm carbs (the way "Bandaid" gets used to refer to any adhesive bandage). "BS" isn't an acronym, the letters are just Mikuni's series designation for OE diaphragm slide carburetors; many variations produced over many years. Of course folks who are struggling with a particularly nasty set tend to attach other meanings to those letters.

 

[solidstateirons]

Gotcha!! Thanks all for the explanation!! Have things much clear now!