Filter
Top Products
Carburetor Jetting Clutching Chart
AMBIENT
TEMPERA-
TURE
Below
-20°F
Below
-29°C
-20°Fto
+10°
-29°Cto
-12°C
+10°F-
+40°F
-12°C-
+5°C
Above
+40°F
Above
+5°C
Altitude
Meters
(Feet)
Shift
Weight
Drive
Clutch
Spring
Driven
Clutch
Spring
Driven
Helix
Chain-
case
Gearing
0-900
(0-3000)
390
370 340 320
0-900
0-3000
S53H
Almond
R
e
d
#2
B
l
u
e
/
R49 22:43
7
4
P
A
l
t
i
-
(
0
3
0
0
0
)
0
-
3
0
0
0
R
e
d
B
l
ue
/
Orange
7
4
P
A
l
t
i
-
tude
Me-
900-1800
(
3000-6000
)
350 330 310 290
900-1800
(
3000-6000
)
S51H
Almond
R
e
d
#3
B
l
u
e
/
R49 22:43
7
4
P
M
e
-
ters
(Feet)
(
3
0
0
0
-
6
0
0
0
)
(
3
0
0
0
-
6
0
0
0
)
R
e
d
B
l
ue
/
Orange
7
4
P
(
F
e
e
t
)
1800-2700
(6000-9000)
320 300 280 260
1800-2700
(6000-9000)
S49H
Almond
Red
#3
Blue /
Orange
R49 22:43
74P
2700-3700
(9000-12000)
280 270 250 230
2700-3700
(9000-12000)
S49H
Almond
Red
#3
Blue /
Orange
R49 22:43
74P
#3 jet needle position for all
Production = 350 main jet for 0_F at 0-1000 feet with 92 octane non-ethanol fuel, the key switch in the 9 2 octane
position, and the timing curve position “D”.
TIMING INFORMATION
The PRO X 440 has been equipped with two switches that will c hange the timing curve.
The first switch is an ignition switch located on the console.
This switch is used to match the timing curve to the type of
fuel you a re using. The fuel types are 92 octane non-ethanol
premium fuel and 110 octane fuel. D o not run the machine i n
the wrong ingnition k ey pos ition o r engine dam age will oc-
cur.
The second switch is located on the airbox and has seven optional curves. These seven options are used to match the fuel
type and the racing conditions which may vary, depending on the race. The standard position is “D” and should not be moved
unless you are a knowledgeable engine tuner.
Position
Timing Effect
A +3
B +2
C +1
D (Standard Position) 0
E -- 2
F -- 3
G -- 4
The exhaust system has a temperature sensor in the body of the pipe that effects the ti ming curve as the temperature
changes. This feature helps the pipe tune quickly and is not adjustable.
This engine is jetted for operation a t 0degrees andwarmer . Re-jetting isrequired fortemperatures colderthan 0_F.
CAUTION
CAUTION
Mis-use of the t iming s e-
lector switch can cause
serious engine damage.
Running the machine in
the wrong ignition key
position will cause engine
damage.
OFF
ON
110 OCT.
ON
92OCT.
Ignition Switch
Positions