According to the gospel of Snordley P.
Make sure ye not follow an impostor.
First, find your clutch.
Take it off your moped. Clean it up a bit if it’s grimy.
Remove the little clutch arms.
Get a balancer scale thing. Balance it to zero.
Place a clutch arm on each tray on the balancer scale thing. If they are the same weight, yay! If they are not, some filing will need to be done. An angle grinder can be used on the clutch arm that is heavier. The goal is file the clutch shoe until both arms are the same weight.
Reassemble your clutch. Now in the words of Snordley, he says most people would tell you to get the tightening screws flush with the little arms and then tighten three turns. Snordley says this is not the most accurate method. Watch ye, and learn!
Using a fish scale and a piece of hanger, you too can achieve maximum clutch tunedness. Insert the hanger into a little hole in the clutch. The hanger should also be looped around the fish scale. Like this:
Pull the clutch away from the scale until 15 pounds is reached. If you are able to pull much more than 15 pounds, loosen the screw. If you are shy of 15 pounds, tighten the screw. Fiddle with it until you can pull right about 15 pounds. (You may want to experiment and find what you like best, depending on your size and bike setup). We found today that the springs on this particular clutch Snordley was demonstrating on were definitely off balance and the screws were not tightened equally to achieve the same amount of pressure. Interesante.
(photos by joel)