Zenoah G231PUM, G231PUH, G260PU, G260PUM, G260PUH Owner's Service Manual

OWNER’S SERVICE MANUAL

115 50 57-26 (206)

WARNING

• These engines are designed
for radio controlled
products.

• When replacing parts, use
only parts which have been
certified by Zenoah.

• Zenoah assumes that no
responsibility for these
engines that are modified or
used for any other
applications.

• Purchaser has all
responsibilities against any
laws and regulations
existing in the country,
Zenoah is exempt from
such laws and regulations.

• Read and completely
understand this OWNER'S
SERVICE MANUAL before
operating these engines.

MODEL:

G231PUM – for radio control Boat
G231PUH – for radio control Helicopter
G260PU – for radio control Airplane
G260PUM – for radio control Boat
G260PUH – for radio control Helicopter
G290PUM – for radio control Boat

[G260PU]

[G231PUH]
[G260PUH]

[G231PUM]
[G260PUM]
[G290PUM]

1. Safety Precautions

• This manual describes the engine. For its mounting and control, see the
instruction manual for the model airplane, helicopter and boat.

• Each engine is designed for use on each model airplane, helicopter and boat.
If it is used for any other purpose, we cannot be responsible for its reliability,
safety and any laws/regulations in the countries.

•Use genuine parts for replacement.

• Check the propeller, rotor and screw propeller every time. If it is damaged,
replace it with a new one.

• If the propeller (or the rotor or the screw propeller) hit something while the
engine is in operation, immediately stop the engine and check it.

•Start the engine on a flat surface without pebble stones.

• Never modify the flywheeI.

• Check the fIywheel. If it is damaged, replace it with a new one.

• When mixing the fuel, or operating the engine, carry it out in a well-ventilated
place.

2. Engine Assembling

The carburetor, muffler and air-funnel (air-cleaner) are not assembled at factory.
Make sure that the assembling for such parts are done according to the Fig.1.

3

1. Bolt (01252-30550)

2. Muffler (T2075-15110)

3. Gasket (1140-13141)

4. Screw (0263-30408)

5. Engine

6. Gasket (T2075-13150)

7. Carburetor (T2075-81000)

8. Tube (1000-03030)

9. Air-funnel (848ES08300)

10. Spacer (1142-83110)

11. Screw (0263-30555)

1. Bolt (01252-30560)

2. Muffler (T2710-15110)

3. Bolt (T1565-72211)

4. Spacer (1158-15420)

5. Gasket (1140-13141)

6. Spacer (1145-15412)

7. Engine

8. Gasket (T2075-13150)

9. Carburetor (T2077-81000)

10. Air Cleaner (848EP18300)

11. Air Cleaner Body

12. Filter

13. Air Cleaner Cover

14. Screw (0263-30555)

15. Lock Knob

1. Engine

2. Gasket (T2075-13150)

3. Carburetor (T2076-81000)

4. Tube (1000-03030)

5. Air-funnel (848ES08300)

6. Spacer (1142-83110)

7. Screw (0263-30555)

Make sure that gasket and carburetor are mounted as fig.1.
If carburetor is mounted upside down position, the engine does not start as
carburetor does not work correctly.

CAUTION

Fig.1

3. Engine Mounting

G260PU

Make sure that the G260PU is mounted on the aircraft grade plywood with more than
6mm of thickness or a mount of equivalent strength and is firmly fixed with 4 bolts.

[ NOTE ]

1. Be sure to set flat washers or metal plate on the reverse side of the mount to prevent
bolts from sinking into the mount. Before be sure to check for loose bolts.

2. Since the engine is equipped with a float-less carburetor with a diaphragm pump, the
direction of cylinder and position of fuel tank can be freely selected .

3. The Fuel head between carburetor and bottom of fuel tank must be less than 100
mm (4 inches).

4. If the rubber joint is placed between the engine and the body for anti-vibration, check
if the rubber is too week and select the proper hardness of the rubber, in order to
avoid the unexpected vibration under operating engine RPM zone.
Note carefully that if the engine is vibrated at idling, then the idling RPM is likely to
get unstable due to overflow at carburetor by the vibration.

5. Tighten the nut (M8) with a torque of 80~120 kg·cm by
using a spark plug socket wrench, which is applying
about 10~15 kg by hand as shown in the figure.

(NOTE)

Do not tighten the nut (M8) with too large torque, that
may damage the stud.

G231PUM/G231PUH/G260PUM/G260PUH/G290PUM

Make sure that the engine for boat or helicopter is mounted according to the instruction
manual to be provided by boat or helicopter manufacturer.
In case such instruction manual is not available, make sure that engine is mounted by
at least 4 points at engine's PTO side and recoil starter side.

[ NOTE ]

1) Be sure to set flat washers or metal plates on the reverse side of the mount to
prevent bolts from sinking into the mount.
Be sure to check if the bolts are security fastened.

2) The fuel head between carburetor and bottom of fuel tank must be less than 100 mm
(4 inches)

3.2

3.1

4

Nut (M8)

8cm

10~15kg

(80~120kg·cm)

4. Propeller, Rotor & Screw Propeller

5

Propeller for airplane

The recommended prop sizes are as shown in the table bellow.

Be sure to use a propeller which makes the engine speed approximately
7,000~8,500 rpm while the airplane is flying.

When mounting the spinner, set a pin on the hub with more than 3mm of
diameter, thus preventing slipping.

Rotor for helicopter

• Adjust the rotor-pitch to obtain 9,000~10,500 rpm of the engine at full throttle
operation.

• Make sure to use the rotor which is recommended by helicopter manufacturer.

Screw Propeller for boat

The exhaust system (e.g., muffler) is not equipped with as standard. When you
select the exhaust system for the engine, check how many the engine speed (rpm) is
required when the maximum output is generated by using the muffler you select.
And then decide the appropriate the screw propeller that would meet such engine
speed (rpm) that the muffler required.
In general, standard size of the screw propeller (Surface prop type) are as follows:

Pitch ratio ( mm )

1.9 ~ 1.4

Diameter ( mm )

65 ~ 75

4.3

4.2

CAUTION

Diameter x Pitch ( in.)

18 x 6 ~ 10, 16 x 8 ~ 12

4.1

5. Fuel

6. Starting

6

• Mix gasoline (octane over 90) and high grade 2 cycle engine oil (mixing use type;
JASO: FC grade or ISO: EGC grade) at mixing ratio 25~40:1.

• The mixing ratio is according to the oil recommendation.

[ NOTE ]

1) Gasoline may contain maximum of 10% Ethanol (grain alcohol) or up to 15% MTBE
(Methyl tertiary-butyl ether).
Gasoline containing Methanol (Wood Alcohol) is NOT approved.

2) Gasoline is very flammable. Avoid smoking, bringing any fires near fuel.

3) To prevent all possible problems on fueling system, make sure to use the fuel filter
which has more than 300 mesh or equivalent and gasoline proof rubber pipe or
equivalent.
Incorrect fuel filter use causes engine trouble like carburetor's fuel passage stuffing
or piston surface scratching etc.

G260PU

A: HAND FLIP START

Since the G260PU is equipped with the ultra compact C.D.I. type flywheel magneto
ignition system, it should be started according to the following procedure;

✽ The magneto system of G260PU is designed in such a way that when the exhaust

port is closed by the piston, that is, when the compression stroke starts (Refer to
Fig.2-A), sparks are never produced on spark plug no matter how fast the propeller
may be flipped. Be sure to quickly flip the propeller when the edge of magnet on the
rotor is approaching the coil (Fig.2-B). It means that the propeller should be quickly
flipped about 90 degrees in crank angle before the compression is about to start.

Magnet

Coil

Fig.2-A Fig.2-B

6.1