Assembling a KZ engine gearbox. Let's take a look to them.

1 INTRO

The gearbox, a characteristic element of KZ karts, consists of many components and requires a series of operations during assembly. To understand how this is done, we observed the complete reassembly of the gears of the primary and secondary shaft of the gearbox of a TM KZ10C, the newest member of the world’s best 2-stroke competition engine maker.
The first step involves the primary shaft, featuring a toothed gear wheel that is a single piece together with the shaft itself: clamp it in a horizontal position on the side with the smooth surface, so that work can begin fitting the various components on the grooved side.

2 PRIMARY SHAFT

Firstly, fit the two roller cage crescents, holding them steady by hand and sliding on the toothed wheel of the fifth gear. Immediately pour a few drops of oil onto the cage while it is held in position by the gear wheel, then finish sliding the wheel into place and rotate it back and forth making sure that everything works properly (a procedure that needs to be repeated every time you fit a gear wheel).
Next, fit a washer and, with the help of pliers, a seeger ring, ensuring it is firmly seated. Then, put some oil on the rest of the primary shaft to make fitting the rest of the components easier.

3 ALL THE GEARS

At this point, fit the two toothed wheels, made of a single piece, of the third and fourth gears, making sure that the component moves freely on the crankshaft. Fit another seeger ring and a washer, then the toothed wheels of the sixth and second gears.
After once again checking the free movement of the gear wheels on the primary shaft, finish the job by fitting a terminal plug, coating it in plenty of grease.

ASSEMBLING A KZ ENGINE GEARBOX