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ROYAL ENFIELD 350cc and 500cc O.H.V. WORKSHOP MANUAL
VARIOUS CARBURETTER SETTINGS POSSIBLE FOR 350 AND 500 OHV
MODEL
YEAR
CARB
NUMBER
CHOKE
DIAMETER
MAIN
JET
NEEDLE
JET
N E E D LE
P O S IT IO N
THROTTLE
VALVE
PILOT
350 G Stub fitting
1945-46
276AC/1A
15/16"
130
106
3
4
0.037
350 G Flange fitting
1946-54
276BL/1A
15/16"
130
106
3
4
0.037
G deluxe/350 Clipper
1955-57
276AC/1A
15/16"
130
106
3
4
0.037
500 J Stub fitting
1946-50
276BM/1A
15/16"
140
106
3
4
0.031
500 J Stub fitting
1946-48
276CB/1A
1"
150
106
3
4
0.031
500 J Flange fitting
1946-54
276CT/1A
1"
150
106
3
4
0.031
500 J2 Flange fitting
1949-55
276CZ/1A
1
1
/
16
"
170
106
2
4
0.031
500 J2 Flange fitting
1947-55
276DB/1A
1
1
/
16
"
170
106
2
4
0.031
Showing air valve
and throttle closed
Types 274, 275, 276 and 289
The type numbers are found
on the engine connection
Fig 2.
CARBURETTER WITH PILOT JET SYSTEM
Your carburetter may be vertical, inclined or horizontal, but diagrammatically this view applies
to all models, the variation being in the attachment to the engine and of the float chamber.
Fig. 2 above is the sectioned view of the standard Amal carburetter as shown on sheet 1,
figure 1. This is the standard design where the primary air to the main jet and the pilot jet
system comes in jointly through the main air intake, see figure 3, sheet 3. The type
numbers are 274, 275. 276 and 289.
An alternative design is made where the primary air to the main jet comes in through four
visible ports around the base of the mixing chamber, and where also the air supply to the
pilot jet system is separate. The type numbers of these carburetters are 74, 75, 76, and 89.
These tuning instructions apply to both the above designs.
TWO DESIGNS
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