Z1OwnersClub GB

I have these in a box of bits I got with a 1979 GS550, anyone know what they are? Smaller bore is 34mm, larger is 43mm (appprox) at widest points if that helps. They appear to be complete, just in need of a good clean.

Look like Z carbs to me. Think they may be 1000A.

Wanna sell ? I wanna buy if they are.

pm sent mate

If they are 34mm then they are 1000 katana ( They did 32's and 34's). They are much wider spaced than the z9/1000 and have the improved pilot circuit like the early z1's i.e air screw on the side and fuel mixture screw underneath. If you don't sell to TLC i may be interested as i'm running modified 32's on mine.

Where are you measuring them, internally or externally? Looking at them I would say they are 26mm from a Z1000 A1 / 2 this is the internal size on the engine side.

They were measured externally, as accurate as I could get it. Apparantly the 'venturi' is the part to measure? If tlc doesn't want them then zed1015 you're welcome to take a look to see if they'll do the job. Cheers.

I have 1 more pic if it helps;

There not A1 / A2 carbs because the air mixture screw is at the rear so if they're 26mm they are Z900A4, if they're 28s they maybe from a Z1R or Mk2.

Agree with you there Steve.

But what`s with the screw in the bottom of the body similar to the air mixture screw on the A1 2 carbs ?

Steven Cooke wrote:There not A1 / A2 carbs because the air mixture screw is at the rear so if they're 26mm they are Z900A4, if they're 28s they maybe from a Z1R or Mk2.

there not z1r carbs

Hmm, I can' t quite see it clear enough but it does look like it may be screws if they are I don't know then, also I don't recognise the slide height adjusting screw either.

Not z1r ,They do look like 26mm's from the pic's. These carbs have the air mixture screw on the side and a fuel pilot mixture screw underneath. If you look in the venturi you will see two very small drillings. One is linked direct to the pilot jet as normal and the other is metered from the pilot jet via the screw. Its for a smoother transition from idle. A set the same as these with the top idle adjuster came with the drouin zed which is a 1978 1000a.

I'm certain that neither the A1 or the A2 had that dual setup so I can only presume they are from a later model or from a different make of bike altogether.

I'm pretty sure they are Z1000 A4. Got a few sets like this which came with 78/79 registered bikes.

Not z900 a4 as they only have one fuel inlet in the middle of the bank of 4 carbs. Z900 has two fuel inlets, so I think that rules out z1000 a1/a2 maybe?