Exhaust Clamps

[Steve S]

Did Kawasaki modify the size of the exhaust clamps during the production run of the 900,s (cc not the period ),Did they beef them up around the mounting holes? the ones on my Z1A seem a lot finer than the NOS parts I have just brought.If mine were rechromed they have taken a hell of a lot of material off during polishing.....Sorry must learn this picture posting

[zedtwo]

Steve , All the Z1s are 6mm and Z900 / Z1000 are 8mm.

[Steve S]

Thats right,the hole sizes are the same 6mm but the area around the hole is bigger ie more land around the mounting holes.My Z1A (6mm) ones seem to be a 'finer' product.was there any problems with the early ones cracking around the mounting holes I wonder.? wii try and put some pictures on to show the differences.

[Steve S]

Here is a picture of what i mean, on the left are the ones removed from my Bike, the right ones are NOS any ideas why the difference? :

[Garn 1]

I've also noticed this difference in early to late exhaust clamps.

My theory is, when they were reproduced these clamps, they realised the outer inside flanges were not accurate, as they were left in the cast state. Now machining them would make them consistant with the slipper shoulder, and they could more accurately measure the distance from the head surface, insuring equal tension on the two nuts. To do this, they had to alter the mould to allow more metal around the bolt hole. Incidently, this also allows us to support a tidier flanged nut.

As an aside, one thing I've also noticed on the real early Z1 exhaust flanges, is that some have numbers on them.. 1 to 4. However, the numbering on some is not consistent with the numbering on others and not all are numbered in some cases.

RegardZ.
Slight correction to Zedtwo... To my knowledge, all Z900 were 6mm holes, the Z1000 had the 8mm studs.

[GEZ635]

Where did you get them? I had a look at some pmc ones and the ones on the right look very similar to them. There are some sellers, especially in the US who sell pattern parts as originals. Not saying that is the case with yours but they are very like pmc parts.

[Steve S]

Interesting,my view is the ones on the left which came with the bike must surely be original early ones which match the exhausts as they have the stainless steel cover over the weld where the downpipe joins. They certainly look more authentic if you know what i mean even slightly primative compared to the others.
The new ones were brought from two different sellers in the states both stating NOS and from the packaging I have no reason to doubt them but i guess you never can tell.

[steve]

I believe you are correct Steve...this was something that I noticed years ago, the earlier clamps do have a different profile around the holes. The ones on the left in your picture will almost certainly be the originals from your Z1A. I've had one or two that have had cracks in them, so it's reasonable to think the changes were made to provide additional strength.
I also agree with Garn regarding the numbering too...

Steve