O.S. Engines 91SX-H Competition Special - Manual (Page 5)

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Because of initial tightness, a standard
electric starter may have difficulty in
rotating the engine when cold, before it
has been adequately run-in. In this
case, use a high-torque type starter.
DO NOT, however, confuse tightness
with the symptoms of hydraulic lock
caused by an excess of fuel within the
cylinder - often the result of over-
priming.
Attempting to force the engine to turn
over in this condition may cause
internal damage. Instead, remove the
glowplug, invert the engine and eject
surplus fuel from the combustion-
chamber.
Note:
This is a high performance engine
expressly designed for F3C competition.
The engine uses the same mounting hole
spacing as the O.S. 61SX-H RING WC
making them interchangeable.
However, higher gear ratio is required for
the 91SX-H RING C Spec which generates
maximum power at lower rpm than the 61
size engines.
New design 60K-C carburetor has three
adjustable controls which enables
independent adjustment at idling, hovering
and high speed.
INTRODUCTION
As delivered, the carburetor is not fit to
the engine.
Standard accessories
Glow Plug No.8
Woodruff Key
Needle Adjusting Screw (M2.6x5 2pcs.)
Instruction manual
Note:
Carburetor Complete 60K-C
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BASIC ENGINE PARTS
Heatsink Head
Carburetor
Typr 60K-C
Crankshaft
Propeller nut
Crankcase
Thrust Washer
Glowplug
Beam Mount
Cover Plate
As delivered, the carburetor is not fit to the engine.
Secure it as follows.
INSTALLATION OF THE CARBURETOR
Retainer Nut
Carburetor Rubber
Gasket
0.2mm gap
Loosen the retainer nut, press the carburetor well
down into the intake boss, compressing the rubber
gasket as shown in the sketch, before re-tightening
Nut.
Rotate the retainer nut gently until it stops, then
tighten a further 90-120 degrees. Do not over-
tighten the screw as this will damage the carburetor
body.
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2.