FG-40 Instruction Manual
Main body : 1,260g / Muﬄer : 90g / Ignition : 100g
Engine mount set
・Limit gauge (0.1t) for tappet adjustment
・Spanner for tappet adjusting lock nut
・Carburetor adjustment bar
・Ignition system(w/sensor) 1set
・Spark plug[CM-6](Attached to the engine)
・Filter with weight [G36-154]
・Durable tube for Gasoline (1m) [G36-155]
・Aluminum spinner nut [120S-30]
・Tappet adjusting kit [120S-161]
●The fuel is mixture of regular gasoline and high-quality 2-stroke engine oil.
●[Example of oil recommendation]
・ Klotz KL-200 Original Techniplate
・ Deluxe Materials PowerModel 2T-S etc.
●Be sure to use the mixture gasoline : oil =15 20 : 1 by volume ratio. (Ex. 1000ml of gasoline should be mixed
with more than 50ml of oil ).
●During the break in process, use 15:1 mixed fuel to ensure the best lubrication for initial running.
●Any damage caused by the fuel used, in which the oil ratio is lower than 20:1 ratio, is not warranted.
●Do not use gasoline containing ethanol. It may cause not only power loss but also corrosion inside the engine.
Fuel ﬁller line
or adjust with the
mount spacers (option)
fuel supply to carburetor
Close as possible (within 200mm)
●Ignition arrangement- Place the main unit as far from other electrical devices as possible.
(1) Plug cord （meshed high tension cord)
Insert the plug cap of the plug cord deeply into the plug
attached to the cylinder to make sure it will not come oﬀ.
(2) Sensor cord
Connect with the cord from the sensor attached to the
(3) Battery cord (black / red cord)
Use a fully charged battery that has adequate spec. (6-12V,
more than 1000mA is recommended). Between the
battery and main unit, make sure to set a heavy duty switch
whose capacity is higher than 3A.
Connect the digital tachometer (Option). Otherwise the
connector is normally vacant.
3. Method of choke （ No need when you use starter）
●In advance, make a thin hole on the cowling to insert the choke bar /
slow needle adjustment bar.
●During choking, be sure to turn oﬀ the switch of the ignition system.
●As shown in the ﬁg, pass the choke bar (with M3.5 thread on its tip)
through the hole on the cowling. Then turn the bar to insert into the
M3.5 internal thread at the center of the throttle lever.
●Fully close the throttle and pull the choke bar and ﬁx it with a clip or clamp
as shown in the ﬁg. so that it may not go back to the previous position.
●Grasp the prop by hand and turn it in the direction of normal operation
(CCW) for several times, until the carburetor generates hissing-like
sound. After hearing this sound for about 5 times, quickly ﬂick the prop
approximately 10 times.
●After that, remove the choke bar. After that, power on the ignition system and ﬂick the prop quickly to start the engine.
If the engine doesn t start, repeat the choking procedure.
4-stroke glow 200 class
1,800-8,000rpm Max on ground Approx. 6,500-7,500rpm
Battery for ignition system
Voltage:6-12V, greater than 1,000mA
・Mount spacer [G40-169]
・Digital tachometer [G17-167]
Filter with weight
To Outside of the plane
Voltage : 6-12V
Capacity : 1,000mA∼
ﬁxed by clip
4. Break-in MOST IMPORTANT!!
●Prop-recommendation : a well balanced Mejzlik 20 x 8 carbon-made prop for break in.
●Use 15:1 fuel:oil ratio for break in.
(2-3S Li-Po or 5S NiMH)
●Never make the fuel mixture lean during break in. It could cause seizure even during idling or run-
ning at low-speed.
●Before starting the engine, open the main needle Approx. 3 turns and the slow needle Approx. 5 turns
CCW each from full close.
●Start the engine (using a starter is recommended for safety).
●Run for about 5 seconds at low speed to warm up.
●Open throttle gradually up to full open, in the meantime turn
the main needle CCW. Continue to turn the main needle CCW
until the RPM declines (to approx 4,000rpm), keeping the throt-
tle fully opened.
●If RPM doesn t drop, turn the slow needle CCW to make mixture
●Run in this very rich condition for 2 tanks.
5. Needle reference position (Set After Break-in)
●Main needle ： Approx.2 2.5 turns from fully close
●Slow needle ： Approx.4.5 5 turns from fully close （ Then throttle should be fully closed）
●Actually the best condition of the needle varies depending on the prop, temperature, humidity and so
on. Please adjust based on the engine performance during ﬂight.
6. Tappet adjustment
The valve clearance should be checked and adjusted after Break-in and every after 2 hours while the
engine is cold. Before adjusting tappet gaps, tighten the screws around cylinders etc.
1. Remove the spark plug
and rocker arm covers from
the cylinder. Then turn the
prop CCW by hand to place
the piston at TDC of
Top Dead Center
Loosen the lock nut
（both valves are closed)
Switch Capacity : 3A∼
●As the fuel contains oil, the exhaust will produce some residue on the airplane.
●Use reliable and well balanced prop, otherwise it can cause abnormal vibration and may result in serious accident.
●During operation, the screws all over the engine can be loosen by heat expansion of metal. Tighten them up
●When the exhaust valve gets dull by carbon or sludge especially in cold atmosphere, remove the rocker cover and
apply some anti-rust spray to the exhaust valve to help the valve to move smoothly.
●All responsibilities for the use of the engine, and other obligations and responsibilities based on laws, regulations,
etc. are borne by the purchaser and the user, and SAITO SEISAKUSHO CO., LTD. is exempt from any responsibilities.
M3.5 thread for
●If there is any deﬁciency from the factory concerning manufacture, please consult the shop or distributor you
(Move to the left)
purchased from, so that our company will repair them with responsibility. Any failure or trouble caused by unnec-
essary disassembly, modiﬁcation, or other uses than those provided in the instruction manual is not subject to the
FG-19R3 Instruction Manual
22-7, 3-chome, Tokagi, Ichikawa-shi, Chiba prefecture 272-0024, Japan Phone: 047-378-4156 FAX: 047-378-4155
2. Loosen the lock nut and
3. Once the gap is set,
tighten the lock nut and
adjust the gap by hexago-
nal wrench until you get
attach the plug and
the correct gap (below
pic) for both of intake &
Adjust the gap turning
Tighten the lock nut
to ﬁx the set screw
the set screw
All speciﬁcations and models are subject to change without notice.
SAITO SEISAKUSHO, CO., LTD.
4. Turn the prop by hand to
check if the compression
is enough. If the gap is less
than 0, the valve is always
opened sightly and lose
compression. Then adjust
Close to 0 with no limit
Must not be inserted