Ignition System; Spark Plug; Carburetor; Preparation Before Starting The Engine - Saito FG-17 Owner's Operating Instruction Manual

6
S P A R K P L U G A N D C A R B U R E T O R

Ignition System

Saito gasoline four-stroke engines come with
Saito's own ignition system composed of the
ignition unit, cord for sensor (black, red and
white), insulated plug cap, and cord for
battery (black and red). (Battery is not included)
You will also need to secure an on/off switch
(safety switch system).
The switch must carry a rating of 3 amps.
IGNITION SYSTEM
Cord for plug(mesh)
Cord for sensor
Plug cap
Sensor
Battery
Voltage [6-8V]
Bettery
(5cell-NiCd/NiMH or 2cell-Lipo)
Capacity: more than 1,000mA

Spark Plug

1/4-32
Spark gap = .4 to .5mm (.016 to .020 in)
The FG-17 come with Saito's own
1/4-32 spark plug (SAIG20120). When needed,
please replace with identical appropriate
plugs.

Carburetor

The carburetors used on gasoline four-stroke
engines are exclusive to Saito. Since they
have a negative pressure type fuel pump, the
engine can be mounted in any position.
Be sure to mount the ignition system in a
location near the engine and away from the
receiver to prevent any unwanted interference.
Please refer to the diagram below.
Saito recommends the use of a 5-cell NiCd
,NiMH battery with a voltage of 6V, or 2-cell
Lipo battery with a voltage of 7.4V and rated
to a minimum 1000mA.
Unit
Cord for battery
Switch (capacity more than 3A)
CAUTION: If fuel remains in the carburetor
after flight, the components made from
rubber, such as the diaphragm, will
deteriorate over time.
After a flying session, it is best to remove
any fuel remaining in the carburetor by
disconnecting the fuel line and running the
engine until it is dry.
Do not needlessly disassemble the
carburetor. If you experience problems with
the carburetor, return it to the Saito Horizon
Service Center.
Preparation Before
Starting the Engine
(prior to break-in)
• Mount the engine on a strong, flat test
bench or on the aircraft. (In either case,
the engine should be secured so it is
immobile.)
• Check to make sure the throttle barrel will
open and close completely.
• Check the wiring of the ignition system to
make sure it is connected correctly and
securely.
• Make sure the fuel line is connected
securely to the carburetor.
• For break-in, use a fuel/oil mix ratio of
20:1.
• FG-17: Mount a 15 x 6 plastic or wood
propeller . Be sure it has been balanced.
(Remember to check the tightness after
every flight.)
• It is suggested you employ a spinner when
using an electric starter. (Remember to
check the tightness after every flight.)
• Use a tachometer to prevent over-revving
of the engine.
• Be sure to connect a gasoline-proof line
to the breather nipple to vent oil from the
airframe.
• Check the battery of the electric starter to
make sure it is fully charged. Be sure to
use a safety on/off switch from the battery
to the ignition.
7
B E F O R E S T A R T I N G T H E E N G I N E
WARNING: Do not let people stand in
front of or to the side of the engine while
attempting to start it to avoid serious injury.
Also, make sure the engine test bench or
aircraft is completely secure from movement.
Starting the Engine
(assuming the engine is mounted in an
aircraft)
The carburetor on the Saito engine comes
with the low-speed needle adjusted to a basic
setting. The high-speed needle will need to
be set by the user. The standard carburetor
settings are as follows: The high-speed needle
valve is set open counterclockwise from the
fully closed position. The low-speed or idle
needle valve is set clockwise in from flush
from the throttle arm face(reference line).
Please refer to the diagrams.
Note: The minutes listed are in reference to
the minute hand of a clock.
FG-17
High-speed 1 turn
Needle 15 minutes
Low-speed 3 turns
Needle
45minutes
Before you first start the engine, make sure
the spark plug is screwed in and tightened,
and that the plug socket cap is fitted in place
and fastened down properly. Fix the ignition
sensor in the proper position at the bottom
of the engine crankcase. The throttle servo
should be mounted at a distance of 8 to 12
inches from the engine. The spark plug cable
must not touch any part of the model structure
as vibration may damage the shielded cable.
If this is not practical, it will be necessary to
provide an insulation material for the cable.