73 Z1E top end trouble??

was told that the first 2000 built had/have head/jug problems. I have a 73 engine Z1E 00390 of the first 500 built. Have had no problems but was told there is some problem with the head?? anyone know what this guy might have been talking about?? is the head different, was there a change made to the head after the first 2000 were built/imported??

if it has'nt had any problems in its first 35 years of existance then i probably wouldn't worry about anything new cropping up any time soon. as far as i know they did change the block and the head gasket design but beyond that i would not know and you are one lucky guy to have such a low numbered bike i hope your planning on restoring that one. by the way the things that were changed were the block now has a reciever groove for an large o-ring in the cam chain tunnel and the head gasket is now two peice instead of one piece like they were original. send me pictures please. there may be more changes but those are the major ones i know about.

There are a few things with the earlier engines that need checking.

The shim buckets were a poor design on the early engines - Kawasaki replaced most of these under warranty - but it's always worth checking to make sure they older (dimpled) version isn't used.

The idler sprocket shafts are a different design. The original ones are over cut and have a larger damper rubber on them. These can bend/break. The should be replaced.

The head is a little different on the early engines. The vacuum take-off spigots are directly into the intake port. These can leak/fall out.

The external cam chain tensioner is not very strong. In later versions they added ribbing to the casting to beef it up.