I'll show you how to do it.
I made it at Techshop. The have a work bay where you can work on your car, motorcycle, moped... whatever! There are 3 of them around the SF Bay Area, so it's pretty convenient. There's others around the country and they have lots of tools and workshops. Wood, Metal, Fabrics, Electronics and more. It's rad.
Check it out here: www.techshop.ws
Sandpaper and a file
A flathead screwdriver
A piston stop
A socket wrench with a 17mm socket and a sparkplug socket
Step 1: What's Wrong????
When the clutch is together, it moves up and down the notches in the clutch bell, and after time it creates burrs in there. When those burrs get big enough, they hang up the clutch and it don't work no more. :(
Use a file on those notches of the clutch bell, if you have big burrs, just to get it smooth again. Then finish it off with some 220 grit sandpaper. Do the same on the clutch plates if it's rough there. You might need to lightly sand those spots in the friction discs as well.
When you think it's good, put the clutch pieces together and squeeze it to see if it moves smoothly. It should.
Step 2: Disassemble. Reassemble.
Here's a diagram that I used to check my work. You can find other Sachs clutch diagrams online, if your clutch is different.
When I put on the final washer (#13 in the diagram) I had to get in there and press and line things up correctly while someone else turned the 17mm nut on. Just FYI.
Step 3: Righty Tighty, Lefty Loosie...
Step 4: Put That Thing Back In, Through Those Things....
The spring needs to be positioned so it will be applying springyness to the clutch cover...
Step 5: Alrighty...
Screw in all 5 screws loosely, then go back and tighten them down snug in a star pattern. By that I mean, start with the bottom-center screw, then the top-left screw, then the bottom-right screw, then the top-right screw, and finally the bottom-left screw. This is supposed to keep things from warping. Everybody I tell this to calls me dumb for doing this, but that's the way I do it.
Might wanna check your oil level.
I think we're done. Now, go ride your moped-super-bike!!!!!!