31
RECOMMENDED FACTORY JETTING
503
Single carb
with intake
silencer
503
Single carb
w/out intake
silencer
503
Twin carb
with intake
silencer
503
Twin carb
w/out intake
silencer
532/582
Twin carb
with intake
silencer
532/582
Twin carb
w/out intake
silencer
Main Jet
165
185
148
158
145
165
Idler Jet
45
45
45
45
55
55
Needle Jet
2,70
2,72
2,68
2,70
2,68
2,72
Jet Needle
15 k2
15 k2
11 k2
11 k2
15 k2
11 G2
Circlip position
3
3
2
2
3
3
Air Regulating Screw
(turns out)
0,5
0,5
1
0,5
1
1
MAIN JET CORRECTION CHART
Altitude – Ft. above sea
level
0
1500
3000
4500
6000
7500
9000
Ambient Temp C
0
1.01
1.00
0.98
0.97
0.95
0.94
0.93
10
1.00
0.99
0.97
0.96
0.95
0.93
0.92
15
1.00
0.99
0.97
0.96
0.94
0.93
0.92
20
1.00
0.98
0.97
0.95
0.94
0.93
0.91
30
0.99
0.97
0.96
0.94
0.93
0.92
0.90
Example:
Your 503 twin carb has a standard main jet 158 (which is correct for sea
level), if your altitude is 6000 ft. asl at an ambient temperature of 20 degree Celsius,
then multiply by the constant found in the chart 158 x .94 = 148.52
The nearest jet available is 148.
