In 83' they used a cable from the pedal to linkage mounted to the frame that moves the fork.... But I converted mine to a hydro clutch fairly easily.
Hope that answers your question. Let me know if you want advice on the hydro cluth mounting.
Its not so much that they are weak. My problem was that I put in a newer motor. And the linkage for the clutch goes between the motor and frame. So I did not have the hole in the block to thread the linkage ball into. Also if you plan on off-roading this havey it is another reason... If you really flex it up you can pull that linkage apart. The only thing I don't like about mine is now it has a really short stroke and kinda hard to push.. But I got used to it really quick. I just basiclly like the idea of the hydro clutch for wheeling.