Arctic Cat Sno Pro 120 2011 Service Manual page 372

4. To increase air pressure in the shock, pump until
desired pressure is attained.
5. Remove the pump valve from the shock air valve.
 NOTE: As the pump valve is being removed from
the shock, the sound of air loss is from the pump
hose, not from the shock.
6. Install the air valve cap onto the shock.
FRONT ARM SPRING TENSION TOO
STIFF
1. Slows machine down in loose snow.
2. Causes the snowmobile to dart and dive as a result of
less track on the ground on deceleration.
 NOTE: A tight front arm works well under only two
conditions: sticky snow conditions in the spring of
the year and in hill climbing on hard packed snow.
With the front arm adjusted too soft, the spring may come
off the roller.
Adjusting Skid Frame Rear Arm
Shock Spring
(Crossfire/M-Series 600/800 STD)
Proper adjustment of rear arm shock absorber spring pre-
load is necessary to get the most desirable ride.
The rear arm shock spring is adjustable for the terrain con-
ditions and driving style and weight of the operator. The
spring adjuster nut has been set at the factory so the cor-
rect amount of threads are exposed between the adjuster
nut and the threaded shock body as an initial setting.
Rear spring pre-load adjustment is accomplished by loos-
ening the adjuster nut locking collar (B) from the adjuster
nut (A) and using the Spring Adjuster Tool from the tool
kit, rotating the adjuster nut in whichever direction is
desired. Tighten the locking collar against the adjuster
nut.
REAR ARM SPRING TENSION
The rear spring tension is adjusted for the weight of the
driver. Three possible adjustments exist.
1st block position - set for up to 150 lb
2nd block position - set for 150 to 200 lb
3rd block position - set for over 200 lb
7-4
 NOTE: When making any changes to the front or
rear suspension, the change should be made at both
ends to keep the suspension balanced. For example,
installing stiffer springs in front may require install-
ing the next step stiffer spring in back to keep every-
thing in balance.
ADJUSTING REAR ARM COUPLER
The rear arm coupler provides advantages over the stan-
dard suspension.
First, with the coupler system, ski lift under acceleration
is greatly reduced which provides improved handling.
Second, when riding through rough terrain, the rear sus-
pension arm receives some needed assistance from the
front arm shock and spring as the rear arm is fully col-
lapsed and locked up by the coupler blocks. The front
arm then starts to collapse the shocks and spring which
assist the rear springs. The result is a smoother ride for
the operator.
If additional coupler action is desired, the coupler blocks
can be set to the number 2 or 3 position. Each of the cou-
pler blocks has three positions numbered on the inside
surface of the block. When changing the block position,
change both to the same number. To make the coupler
adjustment, follow the procedure below.
1. Using an 8 mm Allen-wrench, loosen the two cap
screws that secure the coupler blocks to the inside of
the suspension rails.
2. Rotate the coupler blocks to the desired position
making sure both are set the same.
0745-159
3. Place a 4-in. block of wood under the rear of the sus-
pension just in front of the rear idler wheels to assist
in collapsing the suspension.
4. Collapse the rear suspension until the rear arm is
firmly against the coupler blocks aligning the two
blocks squarely with the arm. While in this position,
tighten the two cap screws securely.
Manual
Table of Contents
727-720A
738-230A