Switch Capacity : 3A~
Sensor
Battery
Voltage : 6-12V
Capacity : 1,000mA〜
Plug cap
(2)Sensor cord
(Black)
(1)Plug cord
Main unit
(3)Battery Cord
(Red/Black)
(4)Tachometer cord
FG-40 Instruction Manual
Fuel tank
Fuel Level
To Outside of the plane
Vent line
fuel supply to carburetor
Fuel filler line
Vent line
Gasoline-compatible
tank stopper
Gasoline-compatible tubing
Filter with weight
Close as possible (within 200mm)
Hollow out
or adjust using the
mount spacers (option)
Firewall
Engine center
Throttle lever
Slow needle
CCW
to rich
CW
to lean
CCW
to rich
CW
to lean
Main needle
1. Fuel
●The fuel is a mixture of commercial regular gasoline and reliable oil for 2-stroke engines.
●[Example of oil recommendation]
・ Klotz KL-200 Original Techniplate ・ Deluxe Materials PowerModel 2T-S ・ENEOS RACING SPEC PRO-2T (SAITO STANDARD) etc.
If such oils are not available in your country, then please ask the official SAITO distributor in your country for an alternative.
●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 ).
●In Break-in process,
use 15:1 mixed fuel
to ensure the best lubrication for initial run.
●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 ethanol mixed. It may cause not only power loss but also corrosion inside the engine.
Φ40.0mm
32.0mm
40.2cc
19”x10”~ 21”x8”
・Filter with weight [G36-154]
・Durable tube for Gasoline (1m) [G36-155]
・Mount spacer [G40-169]
・Aluminum spinner nut [120S-30]
・Tappet adjusting kit [120S-161]
・Digital tachometer [G17-167]
Bore
Main body : 1,260g / Muffler : 90g / Ignition : 100g
Stroke
Disp
.
Weight (Approx.）
Practical speed
Approx.
1,800-8,000rpm Max on ground Approx. 6,500-7,500rpm
Propeller
CM-6
Plug
Optional parts
4-stroke glow 200 class
Applications
Battery for ignition system
・Limit gauge (0.1t) for tappet adjustment 1pc ・Wrench for tappet adjusting lock nut 1pc
・Carburetor adjustment bar 1pc
・Spark plug[CM-6](Attached to the engine)1pc ・Muffler set
1set
・Choke bar
1pc
・Ignition system（w/sensor）
1set
・Plug wrench
1pc
・Engine mount set
1set
・Anti-loosening nut
1pc
・Hexagonal wrench
1set
Specifications
Standard
accessories
Voltage:6-12V, greater than 1,000mA
※
※If you use a Li-Po, we recommend the spec less than 2,500mA capacity and
less than 30C discharge rate
2. Ignition
●Place the main unit as far from other electrical devices as possible.
●Place the two switches of the ignition and the RC receiver as far
from each other as possible.
(1) Plug cord(meshed high tension cord)
Insert the cap deeply onto the plug to make sure it will not come off.
(2) Sensor cord
Connect with the cord from the sensor attached to the engine.
(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 install a heavy duty switch whose capacity is higher
than 3A.
(4)Tachometer cord (optional)
Connect the digital tachometer (Option). Otherwise the connector is normally vacant.
4. Method of choke
(No need when you use starter
)
※Choking is the means by which fuel is fed to the engine when you start it by hand flipping. Thus it is unnecessary when using starter.
Starting with a electric starter is recommended for safety.
●In advance, make a thin hole in the cowling to insert the choke bar / slow needle adjustment bar.
●During choking, be sure to turn off the ignition switch.
●As shown in the fig, pass the choke bar (with M3.5 thread on its tip) through the hole in
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 several times in the direction of normal operation
(CCW) until the carburetor generates hissing-like sound. After hearing this sound for
about 5 times, quickly flip the prop approximately 10 times.
●Remove the choke bar. Then power on the ignition system and flip the prop quickly to
start the engine. If the engine doesnʼt start, repeat the choking procedure.
3. Propeller
●The Standard prop is Mejzlik D20”xP8” which brings approx. 6,900rpm (or Falcon D20”xP8” brings approx. 6,400rpm).
Larger size or greater pitch can cause engine broken due to overload.
●Use a well-balanced one. Never use the propeller that has been scratched or damaged even if slightly.
●As the propeller is compressed slightly, tighten the propeller nut every hour of operation.
Cowling
Choke bar for insert
M3.5 screw
Throttle lever
Throttle valve
(Move to the left)
Slow needle
Choke bar
Temporary fixed
by a clip
ver. Feb, 2021
5. Break-in MOST IMPORTANT!!
●Prop-recommendation : 20”x8” carbon prop for break-in.
●Use 15:1 fuel:oil ratio for break-in.
●Never make the fuel mixture lean during Break-in. It could cause seizure even during idling or low speed running.
●Before starting the engine, open the main needle Approx. 3 turns and slow needle Approx. 5 turns open (CCW) from fully closed.
●Start the engine (using a starter is recommended for safety).
●Soon after starting, Open the 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 throttle fully opened.
●If opening main needle doesnʼt drop RPM, then open the slow needle too.
●Run in this very rich condition for 1 liter of fuel.
●Now “initial” break-in is done.
6. Adjustment of carburetor after initial break-in.
◇Needle reference position (Set after initial break-in)
●Start the engine after adjusting the needle to the following reference value.
●Main needle：Approx.2~2.5 turns CCW from fully closed
●Slow needle：Approx. 4.5~5 turns CCW from fully closed (Then throttle should be fully
closed)
●Actually, the best position of the needles vary depending on the prop, temperature,
humidity and so on. Please adjust as necessary after observing the engine perfor-
mance during flight.
◇Peak adjustment
●After starting the engine, warm up for approx. 30 seconds at low speed.
●Achieve the peak at full throttle.
→Turn the main needle CW gradually to the position where the RPM is greatest (the peak). Continuing to turn the needle CW past the
peak could lead to seizure so turn it slowly and carefully. If the RPM suddenly decreases after passing the peak,
instantly turn the main
needle CCW
to again increase the RPM. Otherwise it could damage the engine seriously.
●Once achieving peak RPM, return the throttle to low speed. Make a note of the position of main needle at the peak at that time.
( How many turns you did CW based on the reference value. )
◇Slow needle Adjustment
●
After achieving peak RPM, next is slow needle adjustment. Open the throttle from low RPM to full throttle quickly.
●If the engine hesitates for a moment or stalls before the engine reaches max RPM, Itʼs because the mixture is too lean. Then turn the slow
needle CCW slightly.
●If the engine is slow to reach peak RPM (full throttle set), itʼs because the mixture is too rich. Then turn the slow needle CW slightly.
●Adjust the slow needle as above until the RPM follows the throttle movement smoothly. The important point is to adjust the slow needle
AFTER
the main needle has been adjusted to its peak.
●Now break-in at ground level is done. Adjust tappets by the method described later.
◇Pre-flight / Flight adjustment
●
When the slow needle adjustment is done, check the response by revving up from low speed to full throttle quickly several times.
●Open the throttle fully and turn the main needle CCW approx. 60〜90 degrees from the peak position. This is to make the fuel mixture
richer in the air where the RPM get higher than on the ground.
●After all adjustments are made, fly your aircraft and fine tune the engine according to the situation. Basically tuning should be done with
the main needle. Readjustment of the slow needle is rarely needed if the first adjustment of the slow needle has been done successfully.
7. Tappet adjustment
The valve clearance should be checked and adjusted after break-in and every time after two hours while the engine is cold. Before adjusting
tappet gaps, tighten up the screws around cylinders etc.
2. Loosen the lock nut and adjust
the gap by hexagonal wrench
until you get the correct gap for
both of intake & exhaust.
3. Once the gap is set, tighten the
lock nut and attach the plug and
covers.
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
slightly and will lose compression. Then
adjust again.
1. Remove the spark plug and rocker
arm covers of the cylinder. Then
turn the prop CCW by hand to
place the piston at TDC of
compression stroke.
Correct Gap
Must not be inserted
Close to “0” with no limit
Limit gauge
(0.1mm)
Loosen the lock nut
Adjust the gap turning
the set screw
Top Dead Center
（both valves are closed)
Tighten the lock nut
to fix the set screw
Note:
●As it uses oil-mixed fuel, the plane may sometimes get dirty from the exhaust.
●Use a reliable and well-balanced prop. Otherwise it may cause an abnormal vibration and could result in a serious accident.
●During operation, all engine screws can loosen due to metal heat expansion. Check and tighten occasionally.
●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.
●Pay attention to the surroundings so as not to disturb others by noise and exhaust.
●Always keep spectators behind the engine when operating the engine.
