Ski-Doo Formula S 1998, Shop Manual

Page: 132 / 338

Section 04 ENGINE
Subsection 09 (CARBURETOR AND FUEL PUMP)
04-09-3
2,3, E-clip and Needle
Remove screws from needle retaining plate to
withdraw the needle.
The position of the needle in the throttle slide is
adjustable by means of an E-clip inserted into 1 of
5 grooves located on the upper part of the needle.
Position 1 (at top) is the leanest, 5 (at bottom) the
richest.
NOTE: The last digit of the needle identification
number gives the recommended position of the
E-clip
from the top of the needle.
CLIP POSITIONS
The size of the throttle slide cutaway affects the
fuel mixture between 1/8 to 1/2 throttle opening.
1. Low cutaway (high air speed)
2. Rich mixture
3. High cutaway (low air speed)
4. Lean mixture
8, Main Jet
The main jet installed in the carburetor has been
selected for a temperature of -20°C (0°F) at sea
level. Different jetting can be installed to suit tem-
perature and/or altitude changes. Always check
spark plug tip and/or piston dome color to find out
correct jetting.
CARBURETOR FLOAT LEVEL
ADJUSTMENT
9,10, Float Arm and Float Arm Pin
Correct fuel level in float chamber is vital toward
maximum engine efficiency. To check for correct
float level proceed as follows:
– Remove float bowl and gasket from carburetor.
– Make sure that float arm is symetric — not dis-
tored.
– With carburetor chamber upside-down on a lev-
el surface, measure height H between bowl
seat and top edge of float arm. Keep ruler per-
fectly vertical and in line with main jet hole.
TYPICAL
H: Float height
Example:
Needle
identification
Recommended
position of the E-clip
from top
6DH4-3
A00B2GA
1
2
3
4
5
Lean
Rich
1
3
2
4
A00C01A
A01C5AA
H