Running-In ("Breaking-In") - O.S. engine FS-95V Owner's Instruction Manual

Make sure that the
direction or rotation
is correct.
Electric starter
7. Check these conditions and, instead of
pressing the starter button after applying
the starter, have the starter spinning before
applying it to the engine, to give it a
"running start".
When the engine starts, slowly open the
throttle, leaving the needle-valve at its rich
starting setting to promote cool running
conditions. However, if the engine slows
down because the mixture is excessively
rich, the needle-valve may be closed a little
to speed it up until it runs evenly.
All internal-combustion engines benefit from
extra care when they are run for the first few
timesknown as running-in or breaking-in. This
allows the working parts to mate together
under load at operating
Therefore, it is vitally important to complete the
break-in before allowing the engine to run
continuously at high speed and before
finalizing carburetor adjustments. However,
because O.S. engines are produced with the
aid of the finest modern precision machinery
and from the best and most suitable materials,
only a short and simple running-in procedure is
called for and can be carried out with the
engine installed in the model.
The recommended procedure is as follows:
1. Use the same fuel and prop as you intend
for flying your model.
2. Open the needle-valve 2.5-3 turns from the
fully closed position and start the engine.
8. Now disconnect current to the glowplug and
gradually close the needle-valve so that the
rpm increases.
Make adjustments to the needle in small
steps.
Abrupt changes at this stage are likely to
cause the engine to stall. Restart the engine
by simply applying the starter with the
glowplug re-energized and the throttle at its
starting setting.
How to stop the engine
Pull down the throttle lever and trim lever on
the transmitter fully.
Note:
Make sure that the throttle linkage is made
so that the throttle is fully closed when the
throttle lever as well as trim lever on the
transmitter are fully pulled down.
26

RUNNING-IN ("Breaking-in")

3. Open the throttle slowly to the mid speed
position, and disconnect the current to the
glowplug.
4. Now open the throttle slowly to the fully
temperature.
opened position and run the engine for no
more than 5 seconds with the needle-valve
tuned to produced near maximum r.p.m.,
then, immediately, slow the engine down
again
approximately one turn. The rich mixture, so
induced, will cool the engine, at the same
time providing increased lubrication.
5. Repeat this process, alternately running the
engine fast and slow by means of the
needle-valve, while keeping the throttle fully
open, then begin to extend the short periods
of high-speed operation until two tanks of
fuel have been consumed.
27
by opening the needle-valve