KZ650 cafe-racer

Soon all cover bolts were torqued and I put the last piece (chain guide)  in place. Transmission cover looked nice. 



Then I installed an oil pressure switch. 

 

And since I polished the main oil gallery plugs, I had to wrap them with paper tape before I tightened them.  In such a way the plug wasn’t scratched by the wrench socket.

 

 

The ignition rotor in photos came from Kawasaki Zephyr 750. That’s my intention to use ignition, electrical components and modified wiring from Zephyr 750 in this project.

 

Next piece is about exhaust studs installation. I had at hand an M6 stainless steel connecting nut with one end securely welded. I equipped it with a spacer of appropriate length and a bearing ball of suitable diameter. In this way I got a “special tool” for M6 studs installation. It made the process of installing exhaust studs an easy thing: no thread wrecked and marks on the end of studs are similar to those one may find on factory installed studs.

 

 

Then it was time to fit the PMC tachometer port plug and fix it with an appropriate chrome plated bolt (with a small head).

 

To finish this part of story, here are a couple photos of engine:

 

 

 

Perfect wrenching and parts selection as always Nazar 

EDIT: your engine reminds me to a bike party years ago, no pump gas but pump beer, (sorry for the blurry pic,i was a little drunk)

 

Hope it won't take me much longer to finish the project. Or I'll consider possibility to turn the engine into a beer tap:-)

Quality, Quality, Quality!!!

The procedure of camshaft installation and valve timing itself is clearly described in the Factory Service Manual and there is nothing that I could add to it. So I did it all by the book.

 

I got a result which aroused  some doubts in me. From one side, the position of camshafts’ lobes, camshafts’ end notches and timing chain  pins looked  to be positioned perfectly.

 

 

From another side, timing markings were positioned slightly askew.

 

 

 

I am working with timing marks stamped not on  metal, but on rubber parts of the camshaft sprocket for the first time. My initial  thought was that such imperfect marks fitment is a result of imperfect positioning of rubber part on metal part or distortion of rubber cast on metal that might of happen more than 40 years ago. However, since I used Kawasaki KZ750 cylinder head and Zephyr 750 camshafts, I was bound to check matter through and out.

Surely, I checked the simplest things first: I installed the KZ650 ignition rotor instead of Zephyr 750: the marks on both rotors  were positioned perfectly identically.

 

 

Then I checked information on valve timing in all available  books on KZ650, KZ750, Zephyr 750 and ZR7. It turned out that KZ750, Zephyr 750 and ZR7  have identical valve timing specs. Here are screenshots of  timing tables from Kawasaki  Factory Service Manuals:


 

In case if reader is not familiar with specific abbreviations:

 BTDC – Before Top Dead Center
 ABDC – After Bottom Dead Center
 BBDC – Before Bottom Dead Center
 ATDC – After Top Dead Center

The key point is the moments of opening of the inlet valve and closing  of the exhaust valve. As you may see they are completely symmetrical 30° BTDC and 30° ATDC for 750 camshafts or mostly symmetrical 20° BTDC and 22° ATDC for early 650 camshafts.

All I had to do was to check the information from the book. I made the drawing and printed a 360 degree dial that I could mount to the crankcase where the ignition contacts (picker) plate is mounted. The zero of the dial I perfectly aligned with the timing mark on crankcases.

 

Then I checked that the valve clearance for both the intake and exhaust valves of the fourth cylinder is the same and mounted two dial gauges so they indicate movement of valve tappets.

 

With this setup I received results that were not exact as those indicated in books, but pretty corresponding. However, this made me confident that I adjusted valve timing correctly.

 Inlet

 Open: 40° BTDC

 Close: 70° ABDC

 Exhaust

 Open: 80° BBDC

 Close: 40° ATDC

 As you may see, values are different from those indicated in the books. The reason for such difference is a fact that Kawasaki does not state lift of valve at which measurements have to be taken.  But the picture of overlapping  phase of intake and exhaust valves is clearly symmetrical.  For me this means that timing is set correctly and non-perfectly aligned timing markings  is the result of one of two reasons I mentioned before (inaccuracy of placing marks or rubber parts distortion).

 One may note that all numbers I get in result of measurements are for 10° more than those in books. All   except one: closing of exhaust  valve.  Such evenness of three measurements support  that timing is set correctly. As for the moment of exhaust valve closing, it turned out that it opens for around 10° earlier than has to according to books.   So the actual picture of valve timing is more similar to that of KZ650 but with wider phases of valves opening and closing. Why it is not indicated in the Zephyr 750 book  I couldn’t guess, however since “early” opening of the exhaust valves is for good (resulting in cooler exhaust gases), it suits me.

 Later on, with oil in the engine I’ll repeat measurements.