KZ650 cafe-racer

Rectangular cuttings for timing chain idler gears’ shafts turned out to have a shape that is far from rectangular:



Another side of gasket didn’t look better:

I put this Wiseco cylinder gasket on its place and found out that the position of two gasket’ metal rings from four were far from perfect too. Moreover, the gasket was visibly sticking out beyond outlines of cylinder block or cylinder head. It happened that I had a Kawasaki used KZ750 cylinder head gasket, so I placed it atop of the Wiseco gasket and positioned them both with dowel pins. As you may see in the photos below, the Wiseco gasket’ outline is a few millimetres larger than the outline of the OEM gasket.







Sure, I have no use for the gasket that has such issues. And it was a pretty good lesson too: to check parts even if they came from a manufacturer you already trust. I had no choice but order the Kawasaki OEM gasket.

I ordered an OEM cylinder head gasket instead of what comes with a Wiseco piston kit. The part number of this gasket is 11004-1268, and being part number for KZ750 cylinder head gasket it also superseded KZ650 cylinder head gasket part numbers. I ordered gasket from MSP webshop , which lately became my favorite source of OEM parts due to their fast shipping combined with reasonable pricing and shipping fees. Soon my order arrived. It was perfectly packed, but when I opened the box I immediately noticed that the gasket had minor damages. They were visible through original packaging of gasket:



There was nothing in the box that could cause such kind of damage, so the only plausible explanation was that the gasket might have been damaged on the way from the parts warehouse to the MSP facility. From the type of damage I could make a guess that another part was placed upon the upper face of the gasket and it wasn’t fixed very well, therefore during the transportation it made two dents on gasket: one on the metal ring and one on the “soft” area beyond the hole for cylinder stud.

Be the metal ring undamaged, I’d considered the dent on the non metal part of the gasket as non-critical. But the ring, which is made of soft metal, seals the combustion chamber and the damage is on its narrow part, so there is a possibility that it will not seal the combustion chamber properly. In this case it will end up in a breakthrough of hot combustion gases. Therefore, I couldn’t use this gasket.

So we wrote an email to MSP with photos of the damaged gasket attached. MSP answered mostly instantly and offered us a replacement gasket. As soon as they got a new gasket they sent it to us. We in our turn sent the damaged gasket back (return delivery was also paid by MSP). We were pretty impressed by their great approach to the business. One starts to treasure attitude like this nowadays. Thus we hope to continue to make a business with MSP.

And here is a replacement. As you may see, all is OK with this part. However, let’s take a closer look on this OEM gasket. It’s very neatly shaped and looks like a work of art in comparison to that of Wiseco gasket.

From the side of cylinder head metal parts cover the areas around the pairs of combustion chambers. From the side of the cylinder block they look like classic rings. I suppose that the greenish stuff that covers the whole lower side and the area around the timing tunnel on the upper side of the gasket is a factory sprayed sealant.







This gasket is the last significant part in the engine jigsaw, so I hope soon I’ll be assembling the Kawasaki KZ650 engine for our project.

gazzz wrote: So we wrote an email to MSP with photos of the damaged gasket attached. MSP answered mostly instantly and offered us a replacement gasket. As soon as they got a new gasket they sent it to us. We in our turn sent the damaged gasket back (return delivery was also paid by MSP). We were pretty impressed by their great approach to the business. One starts to treasure attitude like this nowadays. Thus we hope to continue to make a business with MSP.

What is their website? Is it MSP in Europe? If so, seems like their catalog goes back to 1985. Did you just search by PN?

MSP is in Europe ( www.motorcyclespareparts.eu/en ), but I don't use their site to search for parts. For part numbers and  supersessions search I use Partzilla, CMSNL, Megazip (this one is in Russian) and so on and so forth. And according to my information 11004-1268 is the latest type of cylinder head gasket which is compatible with my setup.

Merry Christmas to you all! May your garages be full of motorcycles, your heads full of ideas for your projects and your pockets full of “grease” that keeps that projects running non-stop!

Before starting Kawasaki KZ650 engine assembling I have a couple of works to do. One of them is engine covers polishing. I want to get them ready so that after assembling the engine will be stored not only completely ready, but also sealed. And here is the first ready unit: valve cover. It is also the hardest cover to polish due to its configuration, design (which also includes DOHC lettering) and condition. It is a 40 years old cover which was in use for a long time, and was some time ago glass beads blasted. The casting of cover is accurate, but it never was intended to be polished, and unevenness of casting alloy didn’t make things easier. It took me a lot of effort and work to make the cover looks decently. To show you a contrast between “before” and “after” here is a couple of pairs of photos:

And here some detailed photos of how cover looked before I started to work on it:

From the first movements of sandpaper it was obvious what amount of work lay ahead.





Preparation for polishing is a work that requires patience. The path of using coarse sandpaper may look more attractive and fast, but one who takes it will end up with a result which is far from perfect, or having even more work removing scratches from coarse sandpaper. So progress was slow. However, after a lot of dry and wet sandpapering cover began to look much better. It was mostly ready for polishing.

This time polishing was also tricky because I had a lot of corners and tight spaces to process. I did my best and I went right to the edge, after which the time spent on improving the result tends to head toward infinity, while improving itself heads in the opposite direction. So here is, polished Kawasaki KZ650 valve cover, fresh after polishing: