Gearbox shaft Z1-A4

[hanskloss]

Hi all, I need some advice, building an engine out of my A4 lump with broken crank/cracked cases and Z1cases+internals. Both gearboxes are great but the output shaft from Z1 has slightly better looking dogs, I was thinking to fit this complete shaft (being a lazy git) but it is couple of mm shorter where the front sprocked fits. If I remember A4 sprocket has a flange and Z1 is flat, would this explain the length difference?
Another question is the four rubber plugs underneath cylinders, are they only to stop dirt builup or any other purpose?

[z1bman]

part no for the z1 output shaft is the same as a z900a4 according to babbitts parts catalogue

[Garn 1]

I have noticed a lot of minute changes around the front sprocket shaft to the rear sprocket, from the Z1 to the Z900 A4. The differences, I concluded, were from the introduction of the O-ring chain in the Z1B. The changes were brought in to allow for the small difference in the chain width.

As Z1Bman says the part book indicates no change in part numbers, however, they may not reflect these small changes

I have also noticed small changes in the rear brake cam shaft length and the length of the rear sprocket square-headed retaining bolts. I would be surprised if the Z1 and Z1B parts books do not mention some differences.

The small rubber plugs in the cylinder fins were to dampen the vibration/ noise caused by wind thu the barrel fins at speed.

RegardZ.

[DogsbolloxofZ1B]

The internal cover behind the sprocket is different too, it has different rebates in castings, the most obvious is around the detent spring on the gear change shaft. Not sure but if you change the cover behind the sprocket for an earlier one you might be OK.

[hanskloss]

Strange Kawasaki kept the same part numbers even though shafts length is different enough, also the gears width is about 1-2mm wider on A4 although they line up the same so would interchange no probs.
I thought the extra milimeter or two on the A4 shaft would be to compensate for oring chain, that means I should keep A4 one so the front and rear sprockets line up?
As to the rubber plugs I've placed a major order with Z1 Enterprises but missed these hence the question, I might get a set than

[hanskloss]

Dogsbollox, I should have both Z1 and A4 internal covers so will have a look, thanks for pointing this out

[Garn 1]

The point that Dogsbollocks mentioned is critical in swapping gears from Z1 case to the other ... The difference in that internal casing behind the front sprocket has provision for a three coil spring the A4 has provision for a four coil spring on the gear lever mechanisms. You will not be able to seal the Z1 casing with a four coil spring.
RegardZ.

[hanskloss]

dogsbollox and Garn, thanks very much for the input, here is the photos of the shafts A4 on the left, Z1 on the right

and the plates, now I got them mixed up and am not sure, A4 o the right and Z1 on the left? the only difference seems to be the hole in the pin under the JAPAN ?

[z1bman]

in your photo the gearbox collar on the a4 is not fully seated is this the difference between your measurements

[hanskloss]

no it just moved over roller bearing, the main difference is in the thread length

[DogsbolloxofZ1B]

Hanskloss,
Can you post an image of the two covers taken from the other side. I can't tell from the inside.

Mike

[Garn 1]

The main difference in the Z1 & A4 cases will be illustrated on the lower cases behind the inner sprocket cover. There is a little boss that holds the gear-change spring .... With the Z1, it will only hold a three coil spring, whereas the Z900-A4 and beyond has room for a four coil spring.
RegardZ.

[hanskloss]

Dogsbollocks here is the other side, had a good look round and could not see major difference

[hanskloss]

You were so right Garn,


I had allready fitted A4 change shaft in Z1 case, you guys saved me nerves later when assebling the covers, thanks a lot, I better keep asking thoughout this rebuild

[DogsbolloxofZ1B]

You've got it sorted now by the sounds of it, yes its the length of that stubby that the return spring sits on that is different.