This may or not help, the centrifugal clutch problem is something I've been looking at lately too. There are photos on the link below.
De ligmotor
Automatic clutch has to go.
Front wheel fairing has to go.
There is no clutch lever on the handlebar, as soon as you touch the clutch pedal the clutch disengages and the next gear is selected. To prevent the engine from stalling there is a second, centrifugal, clutch that disengages if the rpm drops below 2000.
To slow the engine down and make it use less fuel I have changed the sprockets from a 14/35 to a 17/28 combination, the first gear is now almost as long as the second gear used to be. Therefore it takes a long time before the centrifugal clutch finally totally engages.
I would rather have a manual clutch and be in control myself.
I have welded the centrifugal clutch and taken out some small parts like a small brake shoe that is used to slow the crank shaft down. Then I have drilled a hole in the engine cover welded some home made parts on and connected a cable to the clutch.
It works surprisingly well, light and precise action as if it was oem. I can even hook a new clutch cable in while peeking trough the dipstick hole.