I bought a 1979 or 1980 A-1 Z1300 this summer. Nice and original condition, but rather well worn, so I have begun dismantling the engine. A rumbling noise from engine made me suspect the primary and secondary chains to be a bit worn. And yes,after removing the sump it was possible to get to the chains and measure the slack whitch was about 19 -20 mm ( the limit is 21 and 22 mm slack acording to the Service Manual ).
This is the first japanese engine I have worked on. I have build many engines but all british or italian. This 1300 is very interesting and complicated and I must say, it's damn heavy. I had to use a crane to lift it from the frame.
Also when splitting the case you have to turn it upside down. Here I was a little worried if the weight of the engine would be to much for the long cylinder stagbolts , so I taped a piece of wood on top of the temporary mounted cylinderblock to relieve the weight from these bolts. as you can cee on the pictures.
I have ordered new primary and secondary chains plus camshaft and timing chain from Helmut in Germany. He has assured me they are japanese made ( and no cheap chinese stuff ).
I must apologize for my avatar which show my other bike. I have no decent pics of the Kawa.