TOPIC:

As far as carb boots and venturi size, most of the boots for a 34mm will work fine for a 32mm. The main issue is the shape of the venturi. Look on the outside. On the KZ750 Mikuni and CV34 venturi, the shape is identical... there is a lip then a small depression, then lip. The later 34s for the bigger displacement bikes have a different shape on the venturi edge and if you use a carb holder for a 650/750 KZ, they tend to not seal well and bulge out. I suspect they won't hold up long.

The other thing with carb holders is to make sure that they have sync spigots built in if the carbs do not. Suzuki carbs (BS series) do NOT have sync ports on the carbs so their carb holder must have them. You can use Kaw carbs on a Suzuki but not the other way around for that reason unless you don't care about sync-ing them.

Well I found out the hard way. Side by side the carb spacing is not even close on the outside two carbs(maybe 3/8 inch each norrower) and about 1/8 inch each for the inner two. My only hope is that maybe the zr7 boots will make the interchange work. If not I have a nice set of 2003 zr7 carbs with 2163 miles on them. Hopefully the boots will let it work though.

I have just measured my ZR-7 carbs.
Diameter of the connection is 32,7 mm. Spacing between 1-2 and 3-4 is 71,9 mm. Spacing between 3-4 is 97 mm.

So maybe this is the reason the ZR-7 has 4 different carb-boots...

KZ750H2 cylinder head and carb holders.




ZR750-H3 (2003) cylinder head and carb holders.




Looks like Kawasaki did some design changes to the head, I wonder if there would be any performance improvement by using the ZR7 head?

You could probably respace the ZR7 carbs to fit the KZ head, but it may be a PITA to do so.

Post edited by: steell, at: 2007/03/25 12:19

trippivot wrote:

exact interchange

same engine same tooling simple as that

I'm with you.
just check out the the embossed bit on the zr750 head were the tacho drive was on the z650!!!!. It's the same

Lets face it, Ben Inamura and his team designed an engine that lasted almost 30 years of production

Jimmy, I think what is being said here is that the carbs don't interchange, possibly because of the carb holders being offset but the spacing is 5mm different (less) than it should be... spacing needs to be 77-93-77 -

Paling1 wrote: Spacing between 1-2 and 3-4 is 71,9 mm. Spacing between 3-4 is 97 mm.

What he probably meant was 1-2 and 3-4 72mm and between 2&3 97mm (PLEASE JUMP IN HERE PALING1 - thanks)

While it is sometimes POSSIBLE to fit carbs with the spacing a bit off, it makes them real hard to seal up. The GS750/850 BS32s will fit in the Kaw carb holders on a Kaw 903/1015 BUT they use angled carb holders on 2&3 and this makes them off 3 or 4 millimeter and you have to use radiator clamps crushed down on the carb holders to seal them. Sometimes you can not get a set to seal very well. Even if you do get them to seal, I suspect it will ruin the carb holders fairly quickly.

wiredgeorge wrote:

Jimmy, I think what is being said here is that the carbs don't interchange,

wiredgeorge, it looks to me going on the replies and my humble experiences, that the heads are the same spacings, I have a Zepher Zr750 1992 head and barrels on a gpz750 bottom end in a z650 frame, and all the hole line up.
I suspect and looking at the fish that steell posted the heads of the zr750/zr7 and kz750 are generally the same, so zr7 intake manafolds should fit the old 750 head.
theres another model out now called a Z750 06/07 which is a compleatly ground up new engine/bike

Could be that they will swap... only commented on what the other fella said. If the cylinder head intakes are canted, as they are on some Suzuki models, it won't matter if the cylinder spacing is the same. The canted runners will place the carb holder ends where the carbs go in at different widths than you would expect. I don't know as I have never even seen one of the bikes being discussed; only bringing up a possibility. If the carb holders are what are canted, then you could possibly use those carbs on many different KZs if you used the carb holders.

wiredgeorge wrote:

What he probably meant was 1-2 and 3-4 72mm and between 2&3 97mm (PLEASE JUMP IN HERE PALING1 - thanks)

Yes you're right, my mistake... all those numbers....