Drive Belt; Torque Sensing Cam Angle - Polaris 1999 Sportsman 400 Service Manual

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cie ntly if it is runnin g faste r than its peak power
range. Decreasing spring tensionallows adj ustment
so that the drive system will shift into a higher ratio
sooner
to
match the engine power,
Torq ue Se ns ing Ca m Angle
The drive pulley spring lension and the cam angle
of the torque se nsing heli x cam work toge ther to
co ntrol how easily the driven pull ey will shift
10
a
faster speed ratio. Refer to Ta ble 4 for the or iginal
po sitio n of the spring ends for the specific model
and year being worked on.
The hel ix cam pushes against the sl id ing sheave .
If the cam angle is steep, the pull eys will shift
10
a
faster speed ratio sooner and will not be as respon-
sive
to increases in load. Conversely, low cam an-
gles
will
exe rt
more
side pressure and
will
slow
shifts until the load is reduce d and speeds are
higher. Refer
10
Ta b le 4 for the standard helix angle.
DR IVE BE LT
Th e driv e be lt transmits power from the dri ve
pulle y to the dri ven pulley. The belt provides a vita l
link in the opera tion and performance of the ATY.
To ensure top performance, the drive pulley. drive
belt and driven pulley must be matched to eac h
other and to the vehicle model. Th e corre ct size
dri ve belt must be insta lled, because belt width and
length are crit ical to proper operation . Belt wea r af-
fects cl utch operation and shifting characteristics.
Sin ce normal wear chan ges the width o f the belt , it
is impo rtant to check the belt frequ ently and adjust
the 1996- 1998 mode l clutch as described in this
chapter. Sec Table 1 for nov.. · drive belt speci fica-
tions.
With
ge neral usc, there is no specific mileage or
time limit on belt life. Belt life is dire ctly related to
maintenanc e and the type of operation. The belt
should be inspected at the interva ls listed in Chapter
Three. Early belt failure is abnormal and the cause
should be de termined to prevent subseq uent dam-
age. For prop er belt cool ing, it is imp ortant that all
of the co vers (Figure 7) arc installed and all joi nts
sca led as desc ribed in Chapter Seven.
CHAPTER EIG HT