O.S. Engines FT-300 Gemini User Manual
Page 10
Regardless of the type of propeller fixing used, make a
habit of always checking the tightness of the propeller
before starting the engine. Remember that, especially with
wooden propellers, there is a tendency for the material to
shrink, or for it to be reduced by the serrated face of the
drive hub.
When removing the propeller from the engine between
flying sessions, it is recommended to withdraw it complete
with drive hub, instead of removing the six retaining
screws. Be careful not to lose the Woodruff key at this
time.
(One spare Woodruff key is supplied with the engine.)
NEEDLE-VALVE AND FUEL INLET
The needle-valve supplied with this engine is designed to
incorporate an extension so that, when the engine is en-
closed within the fuselage, the needle-valve may be adjusted
from the outside. An L-shaped rod, o f 1.6-1.8 mm dia.
and appropriate length, should be inserted into the needle's
centre hole and secured by tightening the set-screw in the
needle-valve knob with the small Alien key provided. For
longer extension, it is recommended to use a piece of flexi-
ble control cable, together with the knob and support hook
supplied. Also, the fuel inlet nipple on the carburettor can
be adjusted to the most suitable position for connecting to
the fuel delivery tube from the tank. Slacken the needle-
valve holder with the 8 mm wrench provided, reset the inlet
nipple at the required angle and re-tighten.
GLOWPLUG WIRING
A set of glowplug leads, with clips, is supplied with the
engine. The lug plate of the earth lead should be fastened
to the motor mount by means of one of the engine fixing
screws.
Observe the following precautions:
1) Make sure that no part of the wire or glowplug clip
touches the cylinder head or cooling fins.
2) Keep wiring away from the fuel tank, where it might
cause a fire in the event of a short-circuit.
Battery Capacity
It is advisable to use a glowplug battery of fairly large
capacity (e.g. 20 AH in the case of a rechargeable lead-
acid cell) as this is required to heat two glowplugs simul-
taneously.
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