ACCELERATOR RETURN SPRING S1, S11 & E
This was anchored to a bracket retained by a sump bolt on the S1 & S11 UB Motor.
The bracket has a small hole to attach the spring.
It would seem probable that this was a factory fitment.
Refer to the illustration on page 5 of the Series 1 Owners Handbook to see the form it took. Over the years, it has probably been mislaid or left off (blame the mechanic).
A shorter spring with the correct tension can be used with a wire extension (looks tidier).
The Series E had the spring attached at the bottom of the air cleaner duct.
Joe Greenaway – Master of Parts