Saito G-41X Instruction Manual

FG-41X Instruction Manual
Specifications
Φ40.0mm Stroke 32.8mm
Bore
Main body : 1,340g / Mount spacer : 95g
(with screws
Weight (with sensor)
(Approx.）
Muffler : 90g / Ignition : 100g
19"×10"〜20"×8"
Propeller Plug
・Spark plug[CM-6] (Attached to the engine) 1pc
Standard
・Ignition system (w/sensor)
accessories
・Choke and carburetor adjustment bar 1pc
・Filter with weight [G36-154] ・Durable tube for Gasoline (1m) [G36-155]
Optional parts
・Tappet adjusting kit [120S-161] ・Digital tachometer [G17-167] ・Aluminum spinner nut [120S-30]
1. Fuel
●The fuel is a mixture of regular gasoline or high-octane gasoline and high-quality 2-stroke engine oil.
●[Example of oil recommendation]
・ Castrol POWER1 RACING 2T ・ Deluxe Materials PowerModel 2T-S ・ Klotz KL-200 Original Techniplate etc.
If such oils are not available in your country, then ask the official SAITO distributor in your country for an high-quality synthetic oil specifically formulated
for 2-stroke engine fuel mixtures.
●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 will not be covered by warranty.
●Do not use gasoline containing ethanol. It may cause not only power loss but also corrosion inside the engine.
Equipped with fuel tank
Do not use
fuel filter here
50 or less
mm
Important to place the carb and fuel tank as close as possible.
Caution: If the distance between the cab and the fuel tank is large, the fuel may temporarily drain during flight and may cause engine stall or seizure.
2. Ignition
●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
engine.
(3) Battery cord (black / red cord)
Use a fully charged battery that has adequate spec. (6-9V,
greater than1000mA, 25C or less). Between the battery and
main unit, make sure to set a heavy duty switch whose
capacity is higher than 3A.
(4)Tachometer cord
Connect the digital tachometer (Option). Otherwise the
connector is normally vacant.
3. Propeller
●Recommended propellers are Mejzlik carbon 20"x 8"(around 6,900rpm) Falcon carbon 20"x 8"(around 6,800rpm).
●Choose a reliable propeller that brings maximum rotation speed of 6,500 to 7,500 rpm on the ground. The propeller must match the airplane.
●Use a well-balanced one. Never use the propeller that has been scratched or damaged even if slightly.
●Do not use propellers that are either too small or too large in load, as this can lead to engine failure.
●After use, regularly check for any looseness in the propeller nut and tighten if it is loose. Pay special attention to wooden propellers as they are prone to
compression.
41. 2cc
Disp. Applications
nuts) RPM Range Max on ground
& 1,800 - 8,000rpm
(Approx.） (Approx.）
6 - 9 V, greater than1,000mA
CM-6
Battery for ignition system
（ 2S Lipo 25C or less, 2S Life, 5S NiMH ）
・Muffler set 1set ・Tappet adjustment tool
Hexagonal wrench (2.0mm) for Tappet adjustment
1set ・Engine mount spacer set 1set
spanner for Tappet adjustment
Limit gauge (0.1t) for Tappet adjustment
Vent line details
Fuel filler line
Vent line
Gasoline-compatible Fuel Tank
tank stopper
Fuel Level
Gasoline-compatible tubing
Filter with weight
To Outside of the plane
Ignition configuration
Plug cap
(1)Plug cord
Main unit
(2)Sensor cord
(Black)
Sensor
4. Method of choke
ver. Jan, 2025
※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.
Acrobatics - 2st 30㏄ class
●As shown in the fig, pass the choke bar (with M3.5 thread on its tip) through the hole in the
Scale - 2st 30〜40㏄ class
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
6,500 - 7,500 rpm
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.
1set
●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.
5. Break-in
●Prop-recommendation : 20"x 8" carbon
●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 the slow needle
Approx. 5 turns CCW each from fully close.
●Start the engine (using a starter is recommended for safety).
●Soon after starting, 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 throttle fully opened.
●If RPM doesnʼt drop, turn the slow needle CCW to make mixture much richer.
●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.
●Peak adjustment
Vent line
◇After the initial break-in, keeping the main needle unchanged, open the slow needle Approx. 5 turns CCW from fully closed (Then throttle should be fully closed).
◇Start the engine (using a starter is recommended for safety).
◇Achieve the peak at full throttle. →Turn the main needle CW gradually to the position where the RPM is greatest (the peak). Turning over the needle CW
past the peak could lead to seizure so turn it slowly and carefully. Once the peak is passed, the RPM will drop suddenly. In that case immediately return
(CCW) the main needle.
◇Once achieving peak RPM, return the throttle to low speed. Adjust the slow needle following next chapter.
●Slow needle Adjustment *Please be careful not to press the slow needle too forcefully during adjustments, as this may cause the engine to stop.
◇After achieving peak, open the throttle from idle to full open quickly several times to check responce.
◇If the engine hesitates for a moment or stalls before the engine reaches max RPM, the mixture is too lean. Then turn the slow needle CCW slightly.
◇If the engine is slow to reach max RPM, the mixture is too rich. Then turn the slow needle CW slightly.
◇Adjust the slow needle in above way until RPM follows the throttle movement smoothly. The important point is to adjust the slow needle in the condition
where the main needle has been adjusted to its peak.
◇After the slow needle is adjusted, stop the engine and make a note of the main needle position at the peak. (So that you can refer to how many turns CCW
from fully closed position when you lost right position.)
●Pre-flight / Flight adjustment
Switch (not included)
Capacity : 3A〜
◇Before flight open the main needle CCW approx.1/6 turn 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.
The slow needle also requires fine tune when there is a large temperature difference, such as in summer and winter.
◇The break-in process and needle adjustment are done now. Proceed with the tappet adjustment using the following steps.
◇The best tune depends on various factors such as propeller, temperature, humidity, etc., so please adjust the needles according to the situation.
(3)Battery Cord
7. Tappet adjustment
(Red/Black)
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,
(4)Tachometer cord
tighten the screws around cylinders etc.
(Brown/Red/Orange)
1
Battery (not included)
Voltage : 6 - 9 V
Capacity : 1,000mA〜
Discharge : 〜25C
1. Remove the spark plug and rocker
arm covers of a cylinder. Then turn
the prop CCW by hand to place the
piston at TDC of compression stroke.
(No need when you use starter)
Recommend adjusting to 1/3 of the tank capacity.
Provides a needle position close to the real thing.
This reduces the mixture ratio lean during flight.
2 3
2. Loosen the lock nut and adjust 3. Once the gap is set, tighten
the gap by hexagonal wrench the lock nut and attach the
until you get the correct gap for plug and covers.
both of intake & exhaust.
Chalk composition
Throttle lever
Cowling
Choke bar for
insert M3.5 screw
Choke bar
Throttle valve
(Move to the left)
Slow needle
Temporary
fixed by a clip
Carburetor adjustment
Slow needle
*The engine is upright
CCW CW
Throttle lever
to rich to lean
Main needle
CCW CW
to rich to lean
4
Correct Gap
Close to "0"
with no limit
Limit gauge (0.1mm)
Must not be inserted
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 again.