KZ650 cafe-racer

As I already have written I decided to polish KZ650 engine covers before engine assembling. So here we go with a sprocket cover. This cover is more than 40 years old and it wasn’t laying in the box on the shelf all this time. So, no wonder, it is all over scratched and oxidized. Here is how sprocket cover looked after being treated with pressured gasoline and by high pressure washer:

My task was to detect if the cover is not beyond salvation. Well, it turned out that work was within my skills:



Another couple of photos “before and after”:

However, it wasn’t an easy walk, a lot of sandpapering was involed. Here you may see how deep some of scratches were:



But patience did the trick and with some efforts applied sprocket cover started to look more decent.

After courses of dry and wet sandpapering I made the first polishing approach to reveal and eliminate flaws that could be eliminated. Then I made the final polishing.

Same story was with the cover of the clutch adjuster. Initially it looked battered, but fortunately, wasn’t beyond salvation too. Sandpapering and polishing made it look pretty different. Here are photos before and after the work I did on it:

What do you mean by "being treated with pressured gasoline"?

I mean an air washing gun filled with gasoline (or sometimes with kerosene). I definitely couldn't recommend this trick, however it is mighty useful against the grease. I use it because the garage area is far from inhabited zones and has hard pavement. I wash parts with gasoline strictly outdoors and with face protection, including protecting glasses alike to vintage pilot goggles. I also use a large galvanized tub to prevent gasoline from spilling all around.

Your amazing polishing skills are out of this world. It´a plesure to enjoy the before and after pics. :woohoo: :woohoo: :woohoo:

Incredible! How long did it take for this sprocket cover?
Any tips or special techniques for polishing in curves and tight spots?

Thank you, Scirocco!

katit: I couldn't say  how long it took to finish the cover as it wasn't continuous work: to run  the project and workshop I make some parts and do the work to order.

Here is a copy of my answer about polishing:

Polishing" is 90% surface preparation and only 10% polishing itself. The better you prepare surface - the better is result. Usually I do it in this way: firstly I remove cast defects, seams and so on where it’s possible. This work I do with help of sandpaper wrapped around rubber blocks, delta sanders (have two of them) and Dremel. Then I sandpaper dry with sandpaper up to 800 grit manually and with delta sanders and Dremel. After dry sending I do wet sending (up to 3000 grit).

Then it’s time for first polishing. I use various headpieces for Dremel for hard to reach places. For other cases I mostly use buffing cloth wheels installed on bench grinder. Once surface polished all defects (traces of sandpaper and so on) became visible. I remove those of them that could be removed and do second polishing.

Some aluminum parts need to be polished long and in all directions to became perfect, while for other parts long polishing makes no good, as it exhibits tiny defects (like pores). Of polishing compounds I use two: mostly liquid Doctor Wax Metal Polish and solid past (supposed to be Diamond polishing compound , dunno of what concentration, but it works just good ).

Here are some additional tips and tricks:

www.gazzz-garage.com/2019/03/23/kz650-ca...ome-tips-and-tricks/

Just jumped in! I can’t believe someone can take an engine so much apart, put it back together and still works. I’m beyond amaze. And the picture of the carb bits, WOW. Nice polishing job, I have done it and it takes a lot of hard work, but well rewarded.

Can’t wait to see the final product. And I’m glad you are paying for it, not me. Won’t be cheap, but well worth it. You’ll have a unique and beautiful bike. My wife almost lost it when I told my last build cost $3500

JL

Thank you! And talking about paying:-)

How many parts could be necessary for engine overhauling? In my opinion the answer depends largely on how far the owner is ready to go.

And as I was making a pre-assembly check of parts I bought for our Kawasaki KZ650 project, I could take a pretty illustrative photo of how the answer for the question looks in my case.

So, how many parts do I need in addition to the next short list to be satisfied?

• Wiseco K700 piston kit;
• New KZ750 cylinder head and new OEM valves;
• KZ750 (Zephyr750) camshafts;
• Zephyr 750 oil pan (to attach an oil cooler);
• Set of aftermarket gaskets I bought even before I started the project;
• Damper rubbers for clutch basket;
• Parts to repack starter motor;
• New clutch cover and used alternator and ignition side covers.

The answer is in the photo below. And mind three things:

• it’s only parts that are to be installed in or mounted to the engine or/and to its covers;
• some parts are still on their way;
• surely, I found that I still miss a couple of things so I am about to order them.

And still there are enough parts to completely cover one of my working tables.



Among parts one may find complete set of OEM oil seals and O-rings (as well as other OEM rubbers), bearings, OEM cylinder head studs, nuts and washers, complete set of new OEM bolts for crankcase and all side covers, intake manifolds, new kick pedal and starter motor cover, new OEM fibers for clutch and PMC clutch pusher, upgrade parts (mostly PMC) for timing chain tension system and D.I.D timing chain itself, and so on and so forth up to wire clamps, dowel pins, lock washers, snap rings and low gear for output shaft.



One may call it madness, but even if it is so, that’s the madness in which I prefer to dwell by my own will.