LEFT
TO RIGHT:
#161-03 2000 SU Spring,
#161-02 Non-smog 1500 & 1600 Spring,
#N1611 SSS Spring for 510 610 Bluebird etc.
#161-B1 68-70 USA 1600 Smog Spring (use
161-02)
Nissan
springs, correct length and correct strength.
Incorrect spring force can accelerate throttle shaft
wear and your pedal won't feel "right". If your
throttle doesn't return properly it usually isn't the
springs that are at fault. Binding linkage, improper
adjustment, no slack in throttle cable, dirty throttle
cable inner wire are typical causes. If the problem
has persisted since the carbs were last disassembled
it may be the throttle plates binding. The SSS Spring
N1611 is what came on carb sets from Japan for the SSS
Bluebird (510 610 710)