Inside the KZ engine

   What goes into one of our rebuilt engines for our KZ project bikes? We have created these pages to give you a better idea of what's inside, and why we do it that way. The engine in these pictures is now in a 1977 KZ1000A that we built in the summer of 2004.  All of the parts used for this engine project are kept in stock at Redline. We often describe our engines as having a "welded crankshaft". In the pic at left, you can see the two
spot welds on the pin. KZ cranks, as well as many others, are assembled from individual pins, rods,
and cheek sections. After aligning, the pieces are pressed together on these pins...the interference
fit pressure alone holds them in alignment. Under high stress, the sections can actually twist on these pins, causing misalignment and imbalances. Welding the pins prevents this. In addition to checking all aspects of the crank for wear, we also run a flex hone through the small end of the rod...this cleans up any minor galling, and promotes oil retention for the wristpin. The "heavy duty camchain" at right is much stronger than stock, and will also greatly extend the life of the guides and rollers that the timing chain moves on. After the cases have been checked for problems, they are glass bead blasted for appearance. This is a tedious process....they must first be given a basic cleaning, then soaked in a tank of special solvent for a few days. Once thoroughly dried, and all the thread holes blocked off, they go into the blasting cabinet. Certain areas of the case most be avoided....blasting can affect critical clearances. The "undercut 2nd gears" that are in our KZ engines refer to these gears (they are the two on the left of the shaft). On a 2nd gear shift, a fork moves the 5th gear ( second from the left on the shaft) into the 2nd gear (far left gear).
These engagement "dogs" then mesh. On a sloppy or missed shift, they don't quite make it and the protruding dogs on 5th gear are partially rounded off. Eventually, this rounding prevents 2nd gear from engaging at all. The gears in the pic have had the dogs, and their respective engagemant slots, cut at an angle to lock them in place as they slide together....