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The first run on any engine,
whether 2-cycle or 4-cycle, is crit-
ical to the future of the engine
itself. During this time, metal
mating parts (piston and cylinder,
ball bearings, etc.) wear in. Care
must be taken that the engine is
clean and free of any dust or grit
that may have accumulated while
building the model.
There are two accepted methods
for breaking in a new engine:
either running it mounted on a test
stand or in an aircraft. Either
method is acceptable; however,
mounting the engine to a test
stand allows the engine to be
observed throughout its operation,
as well as elevating it above the
ground and away from harmful
dust and dirt.
NOTE: Because your engine may
have been sitting for an extended
period of time prior to running it,
a few drops of light oil applied
through the crankcase breather
nipple (19 on the exploded view),
if applicable, and down the
pushrod tubes (40) will ensure
proper lubrication for the first run.
Regardless of the mounting met-
hod chosen for break-in, the
following procedures are applicable:
1. Use a break-in fuel as
described in the ”Support
Equipment” section, of
this manual.
2. Use the proper glow plugs.
Your engine includes the Hangar
9/McCoy MC-4C (HAN3010)
glow plugs, which are standard
replacement glow plugs for
these engines.
3. Select the correct propeller. To
do so, refer to the Propeller
Selection Chart on page 15 of this
manual.
4. Ensure that the high-speed nee-
dle valve (85) is opened (turned
counterclockwise) five full turns.
This guarantees a very rich set-
ting.
DO NOT adjust the low-speed
needle valve at this time. The low
speed needle valve is pre-adjusted
at the factory for initial break-in.
5. The use of a tachometer is
highly recommended since the
adjustment of a 4-cycle engine,
while similar to that of a 2-cycle
engine, is more difficult to
“set by ear,” making it easier to
damage the engine by ”over lean-
ing.”
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Saito manual doc 11/12/01 2:11 PM Page 6
