Cross-Year Cylinder Head Compatability (kz550 1980)

Hey all,

Are there any compatibility issues I should look out for when mixing cylinder heads? I own a 1980 kz550 and broke a bolt in the carb manifold holder. Its mucked up and it may be more economically viable to replace the whole head. Is a head from a 1982 compatible? What issues should I consider when making this decision? I am not knowledgeable in this area.

I looked on the parts diagrams and they are the same number but I wanted to check here and make sure. Im looking at something like this
Link Here (ebay)

Is it on the #4 cylinder? It usually is.

It's been a long time since I looked into this and memory is slipping, but I *think* the Kz550 heads should be totally swappable. Some of the internal parts have different numbers, but from what I can tell they are practically identical. If I recall, the later parts often supersede the earlier part in most cases. Just double check the head gasket part number. That will usually tell you. I only ever use the Kawasaki website parts fiche, but there are others that are more thorough (kawasaki's website used to be very thorough, but it was changed and is abbreviated now).

I've rescued quite a few broken intake bolts from heads... including some after someone already broke an extractor off in the bolt... and haven't needed to replace a head yet. Can you post a good macro-photo of the broken bolt?

One thing to be aware if an extraction is attempted... even if you can get perfect purchase on the rusty nub, turning it can often split the aluminum casting, so backing out a really stubborn one is not necessarily the best strategy. On a recent Kz400, I had to drill away the entire core of the bolt while leaving the threads mostly untouched. Then I use a really sharp tool or a specially prepared bolt (aka "thread chaser" with a large section removed) with "claws" to scrape the remaining rusty threads out of the aluminum threads. The remnants usually end up like a small ball, or actually look like a fist. That can then be picked out with a tiny spring wire shaped into a hook.

Sometimes you can get lucky and an extractor will work. I usually try it first. But often on those right side intake bolts, they have to be hogged out and scraped.

Bottom line is that it takes a LOT of patience. Take many breaks to think about each step and all of the ways it can go wrong. It may take me hours to get one bolt out, taking my time, but the end result is a perfectly in-tact aluminum casting with decent threads.

Here's what the bolt remnants look like:

www.kzrider.com/forum/2-engine/612150-br...-and-recommendations

Yup... I already tried the bolt removal and it did not go swimmingly. See the post above for that. The cylinder head parts #'s are the same so I am planning on swapping heads... I appreciate the insight especially since I have already found myself in a hole

Yeah, I see. That crack will have to be addressed, but a good welder should be able to fix that without too much trouble. Getting the bolt out with the hole off center will be a much more difficult task. A decent mechanic could weld a piece of metal to the remaining bolt and use that to spin it out.