O.S. Engines FS-52S - Manual (Page 10)

NEEDLE-VALVE EXTENSION
The needle-valve supplied with this engine is
designed to accept an extension so that, when the
engine is enclosed in a cowling, the needle-valve may
be adjusted from the outside.
An L-shaped rod, of appropriate length, may be
inserted in the needle-valve knob center hole and
secured by tightening the set-screw with a 1.5mm
Allen key.
Before connecting the throttle to the servo, make sure
that the throttle arm and linkage safely clear any
adjacent part of the airframe structure, etc., as the
throttle is opened and closed.
Connect the linkage so that the throttle is fully closed
when the transmitter throttle stick and its trim lever
are at their lowest settings and fully open when the
throttle stick is in its fully-open position..
Carefully align the appropriate holes in the throttle
arm and servo horn so that they move symmetrically
and smoothly through their full travel. Fit these in the following sequence.
Screw the header pipe into the cylinder head until it
bottoms, then unscrew sufficiently to achieve the
desired exhaust angle and tighten the locknut securely
with a 14mm wrench. Screw the silencer onto the outer
end of the header pipe and tighten the second locknut.
The application of a heatproof silicone sealant to the
threads of the exhaust system is recommended to
reduce the risk of joints loosening and the leakage of
exhaust gases and oil residue.
Reminder:
Model engines generate considerable heat and
contact with the header pipe or silencer may result in
a serious burn. If you need to tighten the silencer
joints, which may loosen when they are hot, use a
thick folded cloth for protection.
EXHAUST HEADER PIPE & SILENCER THROTTLE LINKAGE
9