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A good working environment
Replacing the kick shaft
This is simple. The kickstart mechanism is self expanatory when looking at it. It's however not entirely obvious that the best thing to do when putting all things back together again is to have the shaft mounted in the right case. Pics will show.
The gearbox and gears wear
The Sachs gearbox is a bit odd comparing to most gearboxes today. The good thing is that the gear wheels could very well last a lifetime since they don't engage and disengage sideways. Instead there is a shifting pin moving in a slot in the gear shaft locking up one gearwheel at the time. This pin is however subject to wear and so is the walls in this slot. The gearwheels has inner grooves that this pin is supposed to lock into. This means that the gearwheels can be subject to a little wear right there. From a reasonable point of view the only thing that really wears out is that pin. Take a good look at it.
Gearwheels stack
The wheels are stacked together with shim rings separating them. The thickness of these shims varies between 2.5 - 3.0mm. What we want to do is combining these shims so that when the pin sliding sideways locks into position for a particular gear the pin is in the middle of the gearwheel. We start by checking out the first gearwheel/pin position.
First push the shifting shaft into the bottom, just like when engaging the sixth gear. Note that I'm pointing at the pin discussed earlier here.
| This picture is not too clear but the thing is, I have the sixth gear mounted. I will check that the pin is well into the wheels grooves when the pin is locked up for the sixth gear. This is a good starting point. |
The picture below shows what it looks like when I have added gear after gear and checking the position for each. This is the wheel for the second gear. The first gear is locked into position on the left engine case and cannot be checked like these ones.
When you are satisfied with the gear/shim stack you need to take them off the shift shaft and stack them onto the 1'st gear wheel. Take care not to move the case around since the wheels will slide around very easily. The picture below shows how It's supposed to look when you are about to mount it together again. Check out my self-made gasket using the original gasket as a template. The picture shows at the bottom of the case, the kick-starter wheel. There is a thin spacer on each side. The gearwheel stack. The first gear wich is also goes into the kickstarter wheel has one ot two thin spacers between itselfe and the bearing. This is to adjust the auxilary gap that should be no more than just so you can feel it. If it's around 0.7 mm, almost up to 1 mm it shouldn't cause any problems except a sloppy feeling gearbox. Note that the primary drive shaft that houses the clutch is there, no need to remove it.
New kickstarter shaft
Check out my new shaft. The old one below..
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