Starting The Engine - Saito FA-120 Special Instruction Manual

4
S T A R T I N G T H E E N G I N E
Break-In
The first run on any engine, whether
2-cycle or 4-cycle, is critical 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: test stand
mounted and run or aircraft mounted
and run. 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) and down the push-rod tubes
(40) will ensure proper lubrication for
the first run.
Regardless of the mounting method
chosen for break-in, the following
procedures are applicable:
1. Use of a fuel as described in the
"Support Equipment" section on
page 3 of this manual for "break-in"
purposes is perfectly acceptable.
2. Your engine includes the Saito
™
SAIP400S glow plug. Use the
proper glow plugs. The Hangar 9 ®
Four Cycle Super Plug (HAN3011)
is a standard replacement to use in
these engines.
3. To select the correct propeller, refer
to the "Propeller Selection" chart on
page 14 of this manual. Remember to
balance the propeller prior to use.
4. Ensure that the high-speed
needle valve (85) is opened (turned
counterclockwise) five full turns. This
guarantees a very rich setting
Do not adjust the low-speed needle
valve (89) at this time.
5. The use of a tachometer (HAN156)
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 much easier to damage the engine by
"over-leaning."

Starting The Engine

1. Make sure the glow plug(s) is/are
installed and tightened.
2. Be sure the propeller is properly
secured. The use of an anti-loosening
nut, or "jam nut," is encouraged on
4-cycle engines.
3. Make sure that the fuel tank line(s)
are properly connected. The fuel
pickup line should be connected to
the carburetor spray bar (84), and
the vent line should be connected to
the pressure nipple on the muffler.
The proper "plumbing" of the
lines is extremely important to the
performance of any engine. Saito
™
recommends the tank be mounted
approximately 5mm lower than the
carburetor center.
4. Be certain that the muffler is
installed properly by oiling the threads
prior to inserting the muffler into the
cylinder head and that the pressure line
is properly connected.
5. Fill the fuel tank.
6. Prime the engine:
• Check to make sure the glow plug
is not connected to the heat source
(glow plug clip/locking socket)
• Open the throttle fully
S T A R T I N G T H E E N G I N E
• Rotate the propeller in a counter-
clockwise direction 5 to 6 times while
plugging the end of the muffler with
your finger to draw fuel into
the carburetor.
Note: Saito single cylinder engines
are now manufactured without the
choke valve (92). Due to the excellent
fuel draw characteristics of the Saito
engines, the use of the choke was
determined not to be necessary.
7. Start the engine:
• Turn through the prop 2 to 3 times
slowly to ensure that the engine is not
hydro-locked (see note below).
Note: When using an electric starter,
care should be taken to be sure the
engine does not become "hydro-
locked" (flooded with fuel). While
the electric starter will turn the engine
over, it may damage the connecting
rod or other components. If the engine
becomes hydro-locked, simply remove
the glow plug and turn the engine over
a few times with the "start stick" or
electric starter. The excess fuel will
be forced to exit the engine via the
cylinder head.
• Close throttle to 1/4 – 1/3
open position.
• Rotate propeller clockwise until it is
against the compression stroke.
5