O.S. Engines 50SX - Manual (Page 9)

The procedure for relocating the needle-valve vertically
is as follows:
As delivered from the factory, the MAX-61FX and
MAX-91FX
RING have their needle-valve assembly
installed horizontally. However, if more convenient for
a particular installation, the needle-valve may be
reinstated vertically behind the cylinder. (See sketch
opposite.) Please note that the needle-valve knob
has a center hole and set-screw for the fitting of a
piano-wire extension (supplied with the 91FX) so that,
when relocated vertically, the extension enables
adjustments to be made without risk of burning one's
fingers on the cylinder head.
NEEDLE-VALVE LOCATION BASIC ENGINE PARTS
Cylinder head
Carburetor
Silicone Tube
Crankshaft
Propeller nut
Propeller washer
Drive Hub
Crankcase
Needle valve
Cover Plate
Fuel outlet
Fuel inlet
Glowplug
Fuel inlet
Beam Mount
MAX-61FX
Throttle
Lever
Throttle Stop Screw
Using 8mm wrench, remove complete needle-valve
holder assembly including needle, from side of
cover plate.
Remove fuel inlet assembly from upper boss of
cover plate.
Transfer banjo type fuel inlet including washers, to
needle-valve holder and carefully screw complete
assembly into upper boss vacated by fuel inlet
assembly. Tighten very carefully.
1.
2.
3.
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