Fine Tune The Carburetor - Arctic Cat Panther 1974 Manual

CARB. INSTALLATION/ADJUSTMENT
Fine Tune the Carburetor
Equ ipment Necessary : Screwdriver, 13/16-inch
Spark Plug Socket and 1/4-lnch Wrench
1. Start the engine and allow the engine to warm
up for approximately 1 minute.
2. Rotate the low speed mixture needle. Fig. 111-
30, 1/8-turn at a time clockwise or counter-
clockwise, whichever will enable the engine to
run smoothly. Allow 15 - 20 seconds between
each adjustment, which will allow the
carburetor to adjust to the new setting. DO
NOT USE A SCREWDRIVER.
_ Note: To richen the mixture, rotate the low
- speed mixture needle counterclockwise. To
lean out the mixture, rotate the low speed mixture
needle clockwise.
Fig. 111-30
3. Using a 1 /4-inch wrench, rotate the idle speed
screw, Fig. 111 -31, until the engine idles at
approximately 2200 RPM, which is just below
drive clutch engagement.
4. With the high speed mixture needle, Fig. 111 -
31 set at 1-1/4 turns from the seated posi-
tio'n, run the snowmobile on a flat hard-
packed area at full throttle for approximately
1/4 mile. Coast to a stop, shut the engine off,
remove the high tension wire from the spark
plug and remove the spark plug, using a
111-18
Fig. 111·31
13/16-inch spark plug socket. Examine the
condition of the spark plug insulator tip.
A. Tan or Light Brown - Indicates correct
carburetor setting.
B. Light Gray or White - I ndicates a lean
carburetor setting.
C. Black - Indicates a rich carburetor
setting.
5. I nstall the spark plug, using a 13/16-inch
spark plug socket. Connect the high tension
wire to the spark plug and close the hood.
6. Start the engine and repeat steps 4 and 5 as
often as necessary to obtain the proper
colored spark plug insulator tip. Remember
that the high speed mixture needle, Fig. 111-
31, is to be rotated 1/8-turn at a time -
NEVER MORE. When the spark plug insula-
tor tip is tan or light brown, the carburetor
is fine tuned (adjusted properly).
II Note: Rotate high speed mixture needle
counterclockwise to richen the mixture and
clockwise to lean out the mixture.
)