Polaris Sportsman 400, Service Manual

Page: 193 / 381

CLUTCH
6.9
RELATIONSHIP OF DRIVE CLUTCH WEIGHTS AND SPRING IN
MAINTAINING OPERATING RPM
The drive clutch is an RPM sensing unit designed to transfer the maximum amount of horsepower from the engine
to the ground. This is accomplished through weights and a spring inside the unit which react to the centrifugal
force applied to the clutch from the engine RPM.
The spring and weights work in combination. In a properly set up clutch, the maximum desired operating RPM
will be reached immediately after clutch engagement, under full throttle conditions. To gain optimum power this
RPM should be maintained. As centrifugal force pushes the weights against the rollers, the moveable sheave
will force the belt to climb up the drive clutch sheave and increase vehicle speed.
If the weights and spring are matched
properly, the engine RPM will go to the
desired range and remain there on both
the upshift and backshift.
If the weights are too light, or the spring
rate too high, the maximum RPM will be
too great and the drive belt will not move
into high gear at the top of the clutch.
If the weights are too heavy, or the spring
rate too low, the engine RPM will be low
and the drive clutch will upshift too fast,
keeping the engine out of its power
band.
Example : Engine Operating RPM 6000 ¦ 200
2000
3000
4000
5000
6000
7000
8000
CLUTCH
ENGAGEMENT
RP
M
2000
3000
4000
5000
6000
7000
8000
CLUTCH
ENGAGEMENT
RP
M
2000
3000
4000
5000
6000
7000
8000
CLUTCH
ENGAGEMENT
RP
M
1000
1000
1000