Quote:
bad speedo head.
 When the head starts binding up, the cable acts like a spring and winds up to the point that it overcomes the 'stickiness' in the head. Then the speedometer jumps, the cable unwinds, and the whole cycle begins again. Might try taking the head out and using one of the spray lubes on it.
On the chance it is the cable, a '75 FSM says to clean the entire core and lube all but the top one foot of the cable and the ferrule.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
| 
