Snowmobile Polaris 2006 - 2007 FS / FST. Manual - part 54

10.17

Rear Suspension

10

Rev. 1 07/2006

TORSION SPRINGS

The torsion spring tension is determined by the following
factors. 

1.

Wire Diameter (B).

2.

Number of coils (F).

3.

Degree of the open angle (G).

A

B

C

D

E

F

G

H

Square Torsion Springs

SPRING PN (last 

3 digits (A) add  

-067 for color

WIRE 

DIAMETER 

inches (B)

LEG 1 

inches (C)

LEG 2 

inches (D)

COIL ID 

inches (E)

# OF COILS 

inches (F)

DEGREES 

OPEN ANGLE 

(G)

SPRING WIDTH 

inches (H)

7042068 LH
7042069 RH

.359

16.5

4.5

1.95-2.01

8.64

47

3.75

7041911 LH
7041912 RH

.347

16.5

4.5

1.82-1.88

7.75

90

3.49

7041627 LH
7041628 RH

.347

16.5

4.5

1.82-1.88

7.71

77

3.45

7042064 LH
7042065 RH

.359

16.5

4.5

1.95-2.01

7.63

50

3.45

7042159 LH
7042160 RH

.347

15.625

3.75

1.89-1.91

6.71

77

3.45

7041902 LH
7041903 RH

.359

16.5

4.5

1.79-1.85

7.75

90

3.5

7041629 LH
7041630 RH

.359

16.5

4.5

1.79-1.85

7.71

77

3.46

7041856 LH
7041857 RH

.359

16.5

4.5

1.79-1.85

7.71

85

3.46

10.18

Rear Suspension

Rev. 1 07/2006

7042079 LH
7042080 RH

.375

16.5

4.5

1.98

8.64

47

3.94

7042101 LH
7042102 RH

.347

15.625

3.75

1.69-1.71

6.71

77

3.45

7042139 LH
7042140 RH

.375

17.7

4

2.35

6.71

77

3.1

7042157 LH
7042158 RH

.359

15.625

3.75

1.82-1.84

6.71

77

3.46

7041631 LH
7041632 RH

.375

16.5

4.5

1.86-1.92

7.71

77

3.74

7041942 LH
7041943 RH

.375

16.5

4.5

2.225

6.71

77

3.52

7041895 LH
7041896 RH

.375

16.5

4.5

2.225

6.71

90

3.52

7042240 LH
7042241 RH

.405

17.7

4

2.35

6.71

77

3.25

7041655 LH
7041656 RH

.405

16.5

4.5

1.86-1.92

7.71

77

4

7041897 LH
7041898 RH

.405

16.5

4.5

2.225

6.75

90

3.55

7041940 LH
7041941 RH

.405

16.5

4.5

2.232

6.71

77

3.55

7043070 LH
7043071 RH

.347

14.75

4.5

1.80-1.84

6.72

80

3.20

7042157 LH
7042158 RH

.359

15.625

3.75

1.82-1.84

6.71

77

3.46

7042242 LH
7042243 RH

.359

17.70

3.25

2.35

6.71

77

3.1

7042253 LH
7042254 RH

.359

14.63

4.5

1.88-1.90

6.75

90

3.00

7042282 LH
7042283 RH

.421

17.70

4

2.45

6.71

71

3.4

7042321 LH
7042322 RH

.347

13.63

4.5

2.16-2.20

5.72

80

2.54

7043042 LH
7043043 RH

.347

14.75

4.5

1.80-1.82

6.72

80

3.2

7043079 LH
7043080 RH

.359

14.75

4.5

1.80-1.84

6.72

80

3.1

7043124 LH
7043125 RH

.405

17.70

4

2.35

6.71

77

3.44

7043128 LH
7043129 RH

.405

14.75

4.5

2.5

6.72

80

3.40

7043130 RH
7043131 LH

.359

14.75

4.5

2.5

5.72

80

3.75

Square Torsion Springs

SPRING PN (last 

3 digits (A) add  

-067 for color

WIRE 

DIAMETER 

inches (B)

LEG 1 

inches (C)

LEG 2 

inches (D)

COIL ID 

inches (E)

# OF COILS 

inches (F)

DEGREES 

OPEN ANGLE 

(G)

SPRING WIDTH 

inches (H)

10.19

Rear Suspension

10

Rev. 1 07/2006

IQ 121 Heavy Torsion Spring Installation

Please reference the following information when installing
heavy torsion springs on IQ sleds. The issue that arises when
installing the heavy spring on a Fusion sled is that the coil stack
of the torsion spring is wide enough to interfere with the

suspension arm clamp nut. To work around this issue you will
need to order two (one for each side) of the following parts.
Relocate the two washers that are next to the clamp nut to the
outside of the link arm.

10.20

Rear Suspension

Rev. 1 07/2006

M-10 SUSPENSION

M-10 OVERVIEW

The FAST M-10 rear suspension has been designed and set up
to deliver a soft ride under average riding conditions. Rider
weight, riding styles, trail conditions, and vehicle speed each
affect suspension action.

The suspension can be adjusted to suit rider preference and
deliver excellent performance for a given set of conditions. It
should be noted, however, that suspension adjustments involve

a compromise or trade off. A machine set up to perform well in
the moguls would not suit the preference of a groomed trail rider.

M-10 ADJUSTMENTS

• Full Range Adjuster (FRA)

• Center Retainer

IMPORTANT: The M-10 rear suspension has been
designed to be very sensitive to rider weight. Changes
in rider weight of 25 lbs. or more may require
appropriate changes in FRA settings.

M-10 TERMINOLOGY

• Couple Blocks: Plastic blocks located at the rear of 

each rail. Blocks facilitate the couple function.

• Full Range Adjuster (FRA): FRA refers to the 

adjustable lower rear shock attachments. Changing the 
FRA location has two effects on tuning. First, moving 
the shock forward increases shock speed, resulting in 
firmer damping on compression and rebound. Second, 
it also increases the effect of the rear spring by 
displacing it further.

• Sag Settings: The difference in rear bumper height 

from the sleds fully extended position to its lower 
height with the rider seated on the sled.

M-10 ADJUSTMENTS

The primary adjustment on the M-10 suspension is the Full
Range Adjustment (FRA). Adjusting the FRA will have the
MOST effect on rear suspension performance.

Polaris recommends that you allow between 25 to 200 miles for
the suspension to break in before performing any adjustments to
the suspension.

This chart is a guideline to be used for initial suspension setups.
Your setup may vary based on your desired riding style.

FTA

RTA

Coupler Block

FRA

X-Over Tube
Pre-Load Adjuster

M-10 SUSPENSION

M-10 128

Rider weight with gear 
(lbs.)

Suggested FRA Range 
(Lower number is softer)

Under 100

1 to 1 1/2

100-150

1 1/2 to 2

150-200

2 to 2 1/2

200-250

2 1/2 to 3

250-300

3 to 3 1/2

300-350*

3 1/2 to 4

Over 350*

4 to 5