I was doing a head gasket replacement onnmy 86 Kawasaki ninja gpz1000 and I while cleaning the gunk off the top of the block I noticed a small gap/crack in between two cylinders (Pictures are linked below).


It doesn't go deep, and I don't think it would have an effect in performance or anything since it isn't near any place where fluid could get in, but it wasn't like this between any other cylindera ans I wanted another opinion. Thanks for any help!

  • Is that a GPZ1000 RX? Commented Apr 29, 2016 at 6:03
  • There are so many model names for it, I'm not sure if the ninja 1000r is just the gpz1000r or does it fall under the RX category too? Any differences? I've heard it be called the zx1000, gpz1000r, and RX, or just ninja 1000r
    – Iqbal Khan
    Commented Apr 29, 2016 at 6:23
  • In 86 the 1000cc inline four liquid cooled 4 valve per cylinder was called the GPZ1000 RX. phew....that was tough. lol Commented Apr 29, 2016 at 6:25
  • That's it then lol, I just got confused over the names, on different forums so many people have called it so many different names
    – Iqbal Khan
    Commented Apr 29, 2016 at 6:53

1 Answer 1


It's completely normal, nothing to worry about

It's simply the gap between the sleeves. If you look from above, straight down, you will see a straight edge cut into the outside diameter of the metal sleeves that are pressed into the aluminum cylinder block. The straight edge is there so the sleeves can co-exist in close proximity without encroaching into the other sleeves diameter. They are rarely perfectly aligned because it's not important that they are. The goal is that they can just sit next to each other after being pressed into the block.

This is case on Kawasaki's, Honda's, Suzuki's and Yamaha's going back to their first inline fours in the late 60's and 70's.

It will have no effect on your performance. It's normal.

  • Thank you! I was thinking that because I noticed the straight edge on the two outer cylinders so I thought it may be similar, thank you for clearing things up!
    – Iqbal Khan
    Commented Apr 29, 2016 at 6:24

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .