Robin EC12 User manual

SERVICE
MAIINJAL
Model
EC12
OIL MIX &OIL INJECTION ENGINES
puB-Esl173
Rev. 8/98

CONTENTS
Section Title Page
1 .
2 .
3 .
4 .
5 .
6 .
7 .
8 .
9 .
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-1
0
4-1 1

MODEL
Type
Number
of cylinder,
Bore x Stroke
Piston Displacement
Continuous
Horsepower
Max. Toque
Direction
of Rotation
Fuel
Fuel Consumption
Lubricant
oil
Lubrication
Carburetor
Method of ignition
spark Plug
Starting System
Governor
Air Cleaner
Dry Weight
Length
Dimensions Width
Height
ECIPD STD.,
EC12D
1 OIL INJECTIONSYSTEM
Air-Cooled, 2-Cycle, 1 -Cylinder, Gasoline-Engine
1 - 54 x 50 mrn (2.13 x 1.97 in)
1 14cc (6.98 cu.in)
22 kW (3.0 HP) / 3600 rpm
. -.
2.9 kW (4.0 HP) I4000 rpm
7.5 I N-rn (0.76 kg-m ) I3000 rprn
Counterclockwise
as viewed from PTO Shaft
Automobile Gasoline
(Mixed
with Oil. Mixing Ratio 25 to 50:l) I
Automobile Gasoline
I
360 g / HP. hr 0 3.0 HP/ 3600 rprn
2-Cycle Engine Oil
Gasoline Oil Mixing Type
(Mixing
Ratio 25 to 50:l)
I O~I separatefuelingsystem
Float Type
Flywheel Magneto
Type (Solid State Ignition)
NGK BMGA I CHAMPION CJ8
~ ~ ~
Recoil Starter
12.0 kg (26.0 Ibs)
273 mrn (10.7 in.)
326 rnrn (12.8 in.)
307 rnm (12.1 in.)
-1-

2.
2-1 MAXIMUM OUTPUT
The maximum output is the output of an engine with its throttle valve fully opened under the condition
that all the moving parts are properly
worn in after the initial break-in period.
A new engine may notproduce full maximum output while its movingparts are still not broken-in.
2-2 CONTINUOUS RATED OUTPUT
The continuous rated output is theoutput of an engine at optimum governed speed which is most
favorablefrom theview point
of engine’s life andfuel consumption.
When the engine
is installed on a certain equipment, it is recommended.thatthe continuous output
required from the
engine be kept below thiscontinuous rated output.
2-3 MAXIMUM OUTPUT
The maximum torque is the torque at theoutput shaft when the engine is producing maximum output at
certain revolution.
-2-

2-4 PERFORMANCE CURVES
Nm (kgf-m)
HP
4
3
0
kW
3
2
1
-0
2000 3000
4000 5000
REVLOUTION
- r.p.m.

3. FEATURES
3-1 COMPACT, LIGHT WEIGHT AND HIGH POWER
Compact and light weight enginethanks to short connecting rod and aluminum cylinder.
3-2 SUPERB DURABILITY
Rugged design on each enginecomponents and employment of high anti-vibration dust cover enable
a long lasting durability even
in harsh applications.
3-3 SfMPLE STRUCTURE, EASY MAINTENANCE
Maintenancefree and high vibration proof have been achieved thanks to the crankcasebuiltin
governor system.
Easy
start with decompression hole on exhaust system.
34 SUITABLE FOR REPLACEMENTENGINE
Robin EC12 engine has the identical mounting flange as EClO engines. Without any modification on
your equipment,
EC12 engine can replace EClO engines.
3-5 OIL INJECTION SYSTEM (OIL INJECTION TYPE)
Oil and gasoline are placed into separate tanks. Therefore, mixing the fuel/oil which often can be
troublesome, is
now done automatically by engine function.
Because thefuel
is gasoline, the start ability of the engine for the reason can be improved.
Since
only gasoline is in the carburetor, there will be no jet choking due to the deterioration of oil.
Themixture ratio has becomeleaner, which will decrease white smokeduring operation.
4. GENERAL DESCRIPTION OF ENGINE COMPONENTS
4-1 ALUMINUMCYLINDER AND CRANKCASE
Aluminum die-cast cylinder with molded-in cast
iron liner has intake, exhaust
and scavenging ports
on the liner. For easy starting, decompression hole
is implemented on the exhaust port.
Crankcase is divided into two pieces
: crankcase 1
(Flywheel side) and crankcase 2 (P.T.O. side).
Governor chamber
is built in the crankcase 2 and
gasoline-oil mixture fuellubricates the governor
system.
Fig. 4-7
-4-

4-2 CYLINDER HEAD
Alumin’um die-cast made cylinder head has semi-
sphere shaped combustionchamber
for optimal
combustion and higher efficiency.
49 CRANKSHAFT AND CONNECTING ROD
Forged steel crankshaft assembled with hardened
crank pin and connecting rod, precision balanced
for low engine vibration, durability, greater shock
loading resistance
and longer life. Needle bearings
are implemented
on both ends of the connecting
rod.
As these parts are press-fitted together by
special jig and are unable to be disassembled,
crankshaft assembly
needs to be serviced in case
crankshaft
or connecting rod need to bereplaced.
4-4 PISTON AND PISTON RINGS
High strength aluminum alloy made piston equips
two piston rings. To avoid piston ring rotation,
knocks arepressed
in piston ring grooves.
Top ring is key-stone type and is chromium plated.
Secondring isa plain type and
is parkerlized.
1
Fig. 4-2
fig. 4-3
Top ring
Key stone type
Chromium plated
Plain type
Parkerlrized
-5-

4-5 ALL SPEED GOVERNOR
Rapid response mechanical flyweight type gov-
ernor system is fully lubricated with oil mixed fuel
for
long' life and which enables more precision
speed regulation
and better reliability.
4-6 COOLING SYSTEM I
Forced air cooling is done by flywheel fan. Alu-
minum die-cast flywheel fan ensures better cool-
ing and durability.
Fig. 4-6
4-7 CARBURETOR
EC12 is equipped with a horizontal draft carbu-
retor that
has a float controlled fuel system and a
fixedmainjet. Carburetor is calibrated carefully
for easy starting,
good acceleration, low fuel con-
sumption and sufficient output.
Fig. 4-7
-6-

4-8 AIR CLEANER
Rugged semi-wet dual stage air cleaner with high
0 efficiency,ease of service and longer enginelife.
4-9 IGNITION SYSTEM
Solid state, high 'energy electric ignition which
referredto as T. C. I. (TransistorControlled Igni-
tion) gives moreprecise ignition timing,
no break-
erpoints
to service,ease of maintenance and
longer spark.pluglife. Ignition system
is consisted
of flywheel magneto and ignition coil. Flywheel is
installed
on crankshaft and ignition coil is on
crankcase. Ignitiontiming is 18 BTDC. (Before
Top Dead Center)
4-10 OIL INJECTION SYSTEM
The oil injection system is a device that uses an oil
pump directly driven by a crankshaft to forcefully
feed lubrication oil to the airintake port of a
cylinder.
Accordingto engine speed, the appropriate amount
of oil is measuredand fed.
Element
\
Fig. 4-8
I
Fig. 4-9
Fig. 4-10
-7-