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Bike Carb Manifold - Quick question
dan8400 - 14/6/10 at 09:00 AM

Can i get away with using longer pieces of rubber hose and not fabricating bendy bits of steel pipe?

Not much of a fabricator/welder and not flush on cash to have it modded atm.

I have a zetec back plate with short pieces (50 - 60mm) straight tube welded to


Thanks
Dan

whitestu - 14/6/10 at 09:23 AM

Which carbs are they? Respace the bike carbs to suit the manifold - it's not that difficult or expensive.

The fuel pipe bits need someone with a lathe to turn them so the o rings fit, but I'm sure you can get that done by someone on here. The rest is basic metalwork to set the carbs at the right distance apart and extend the linkages.

My set up doesn'y have any bits of steel pipe - just the original bolt on Kawasaki rubbers and a piece of Ali plate to bolt up to the head.

Stu

dan8400 - 14/6/10 at 09:26 AM

someone on here very kindly made me some brass spacer pipes for some zx6r carbs which i spaced.

The only problem is they keep coming out of balance. Due to the spacings. I have a set of 1100 carbs i got from a bloke at work for £20 this morning. thought this would solve my problems as i dont fancy spacing/ruining another set of carbs.

Dan

[Edited on 14/6/10 by dan8400]

UncleFista - 14/6/10 at 09:42 AM

If you tried to make a manifold with long hose lengths, I reckon the hoses would collapse due to pressure/vacuum as soon as the engine was started..

whitestu - 14/6/10 at 09:50 AM

quote:

The only problem is they keep coming out of balance.


I have respaced ZX6Rs on my Zetec and they seem fine. Any reason why they are coming out of balance?

If it is any help I have a homemade manifold for non respaced ZX6R carbs. It is designed to work with the ZX6R carb rubbers.

It's not very well made, but works fine. Ideally it could do with brazing internally to smooth the ridges - at present I have done this with chemical metal.

If you are stuck you can have it for £20, which is what the manifold plate cost me. There are some pics in my archive in a folder called inlet.

Stu



Stu

r1_pete - 14/6/10 at 09:50 AM

quote:
Originally posted by UncleFista
If you tried to make a manifold with long hose lengths, I reckon the hoses would collapse due to pressure/vacuum as soon as the engine was started..


Exactly, if the hoses were long enough they would collapse completely stopping mixture getting to the engine.

Either way, the constant collapse / re-expand, would soon lead to hose failure.

Why are your carbs going out of synch?
any pics how you've re-spaced them?
that would be the problem to tackle.

dan8400 - 14/6/10 at 10:29 AM

The problem is the springs that operate the carbs. my zx6r carbs have the cable one end which opens the first carb then there is a spring loaded plate which opens the next and then the next.

The springs dont have the power to stop number one opening slightly more than two and so on

Dan

dan8400 - 14/6/10 at 10:32 AM

I tried putting in self tappers instead of springs but cant get them tight without the throtlle jamming open and not returning.

So i thought a clean slate with a fresh set of carbs (off an 1100 i think) but not spacing them or mucking around with how they operate would be better option.

Dan

r1_pete - 14/6/10 at 12:46 PM

The springs you mention, only keep each spindle cam tang in contact with the adjuster screw on its neighboring carb (For return), it is the screw which presses on the tang and opens each carb.

If you are pressing on the spring you have something assembled wrong.
I have seen these tangs extended when the carbs are spaced, and then they flex due to their extra length. They need some bracing to stop the flexing.

[Edited on 14/6/10 by r1_pete]