Corsair BLACK BULL User manual

BLACK BULL
USER’S MANUAL
Last update September 2020
ENGINE CONFIGURATIONS AVAILABLE
ELECTRIC STARTER
HAND STARTER
HYBRID

Black Bull Manual
1
INDEX
I DENTIFICATION OF THE OWNER AND
INTRODUCTION
2
TECHNICAL AND STRUCTURAL
FEATURES
3
M AIN TORQUES 5
ASSEMBLEY 6
A DJUSTMENT CARBURETOR /
RUNNING IN
7-8
M AINTENANCE
T ENSION OF REDUCTION BELT 11
W ARRANTY 13
T ROUBLE SHOOTING 14
I MPORTANT ADVICE 15
N OTES 1

Black Bull Manual
2
IDENTIFICATION OF THE OWNER
Owner
Address
Serial number
Reseller
Address
Owner’s signature
Reseller’s signature and stamp
Date of sale
Introduction:
Thank you for choosing our engine BLACK BULL CORS-AIR ENGINE.
We tried to do everything possible to give accurate and update technical
information in this manual.
The Company riserve the right to make technical and aesthetic changes without notice in
order to improve quality of product.
The information written here is the exclusive property of CORS-AIR.
So they are not allowed reproduction or replication in whole or part without the express
permission of the CORS-AIR.
This manual has been prepared to provide technical information necessary for the
installation and repair of motors.
We invite you to spend some time reading this to avoid risks to the health and safety of
people and economic damage.
Furthermore, we invite you to deliver this manual together with the engine if you sell it, so it
can be useful for the next owner as well.
The manufacturer and the resellers are ready to answer your questions and, if
necessary, to solve every problem, because YOUR AND THE OTHER PEOPLE’S
SAFETY IS THE MOST IMPORTANT THING FOR US.

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3
CYCLE
T WO STROKE
TOTAL DISPLACEMENT
235 C . C .
BORE
70mm
STROKE
61mm
COMPRESSION RATIO
10.5:1
COOLING
B Y AIR
PEAK RPM max.
8000 /8300 RPM
PISTON
W ITH TWO PISTON RINGS
EAD
I N ALLOY WITH HIGH PERCENTAGE OF SILICONAN
HEMISPHERIC COMBUSTION CHAMBER , WITH SQUISH
CRANKCASE
M OLTEN IN G-A L S I UNI 3051 ALLOY
SUBSEQUENTLY TREATED AND ANODIZED AGAINST
SEA SALT
CONNECTING ROD
I N COPPER PLATED STELL 18 N I C R M O 5 JOINED TO
THE DRIVE SHAFT THROUGH VERY PRECISE HIGH
SPEED SILVER - PLATED ROLLER BEARINGS
CARBURATOR
DIAPHRAGM
FEEDING
S IX BLADE REED - VALVE SYSTEM CONNECTED TO THE
CRANKCASE
SPARK PLUG
N GK BR 8 ES OR SIMILAR
SYSTEM
S IX PORT DISTRIBUATION AND EXHAUST WITH
BOOSTER
CYLINDER
I N ALLOY WITH NIKASIL COATING
REDUCTION
W ITH POLY V BELT AVAIBLE IN 1:3.0
CYLINDER EAD
TEMPERATURE
MAX TEMPERATURE 230°C MEASURED UNDER SPARK
PLUG
E XHAUST GAS TEMPERATURE NOT EXCEEDING 5 0 C°
ENGINE MOUNTING
B Y 4 SHOCK ABSORBING RUBBER MOUNTS
ROTATION
C OUNTERCLOCKWISE
DRIVE S AFT
I N 18 N I C R M O 5 WITH 5 THERMIC TREATMENTS ON
EVERY COMPONENT
SEAL RING
I N V ITON WITH VERY HIGH RESI STANCE AND LONG
DURATION
FUEL
M IXTURE 2,2% / 2.5% WITH SYNTHETIC OIL ,
SUGGESTED BRANDS : M ALOSSI 7.1—W LADOIL

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4
K2T—E LF 2T M OTO
OIL
2.2% - 2,5%
ENGINE WEIG T
H AND START KG 16,7 COMPLETE WITH 2018 VERS .
EXHAUST AND INCLUDING RUBBER MOUNTS AND
AIRBOX IN CARBON
E LECTRIC START KG . 17,4 COMPLETE WITH 2018
VERSION EXHAUST , INCLUDING RUBBER MOUNTS AND
AIRBOX IN CARBON

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5
MAIN TORQUES
IMPORTANT:
Remember that the battery of the electric start should be recharged
before starting the engine.
MAIN TORQUES
Kg. m
(Nm)
N UTS TO FIX THE HEAD 2,5 25
N UTS TO FIX HALF - CRANKCASE 1,2 12
N UTS TO FIX THE PINION ( SMALL PULLEY ) 3,5 35
N UTS TO FIX IGNITION HANDWHEEL (manual
version)
4,5 45
N UTS TO FIX IGNITION HANDWHEEL (electric
version)
2,5 25
G AP BETWEEN COIL AND HANDWHEEL MIN . 0,3 mm
MAX . 0,4 mm
T IGHTENING OF REED VALVES PLATE 1,2 12
P ISTON RINGS GAP TOLLERANCE 0,25 mm

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ASSEMBLY:
You can install the engine on the frame by using 4 rubber mounts of 40 x 30
mm between the back flange and the engine mount.
To attach the propeller use only bolts of class 10.8 (100 Kg) and make sure
that their length is enough to exit from the reductor-pulley. Tighten the 6 bolts
M8 in a cross, at 1.5 Kg.m.(15Nm). Re-check the torque of the bolts after the
first hour of engine’s working.
We suggest not touse a variable pitch carbon prop, because the big hub
pushes the prop too forward, with possible damages to pulley and bearings.
For the connection between the carburetor and the fuel tank use a proper
hose of the right diameter.
The length of the fuel line should not be longer than 80 cm.
It is advisable to install a manual primer bulb to get the fuel to the carburetor
before for starting. This device will allow the fuel to arrive to the carburettor,
protecting in this way the battery.
IMPORTANT NOTES
DO NOT try to start the engine without the propeller.
DO NOT start the engine with loose bolts or parts, since this can cause the
detaching of the propeller, the ovalization of the propeller holes, the damage
of the electric start and the breakage of the rubber mounts.
BATTERY must be loaded and use a 6 Ah battery.
IMPORTANT! BEFORE FLYING C ECK ALWAYS EVERY PART OF
YOUR CRAFT, FROM ENGINE TO FRAME.
Verify that there are no damaged electric wires, that there are no leaks from
hoses, tank, carburettor or engine’s crankcase, that the propeller is not
damaged or loose, that the exhaust-pipe has no cracks, that the frame is not
bent or broken because of falls, that rubber mounts are not cracked, that the
reduction belt is not loose and every bolt is tight.
Finally you can start the engine, leaving it to warm up at a speed of 3000 to
4000 rpm with head temperature at least 0/100 °C, before start taking off so
to avoid piston seizing.

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FUEL
Use for the mixture only premium gas for cars 8 octane, together with good-
quality, synthetic oil for mixtures at a quantity of 2.2% - 2,5%.
DO NOT USE MIXTURE ALREADY DONE AT PETROL PUMPS.
When you prepare the mixture, make sure that the tank has not dirt or water
in it, filter the fuel with cotton white textile into a clean tank and then add the
oil.
Never run the engine without the air-filter, because dirt and dust raised by the
propeller can damage it.
Running- in procedure
The running-in is a key stage of the life of an engine.
Even if the high standard quality level of the machining and the exceptional
material quality currently applied in the production process suggest that there
is no need of an adjustment phase of the engine, the running-in is still a
fundamental step in its life for getting the best performance and reliability.
The parts that require a longer running time for the operation of the
propulsion and that need to get to an optimum settling are cylinder and
piston.
During the running in phase and limited to this period only the fully
synthetic oil percentage is 2,5%
All engines are tested in CORS-AIR before delivery, where we set carburetor
and idle.
We strongly advise not to modify the carburetor settings during the
engine running-in.
1. Turn on the engine and let it run at the ground for 10 minutes varying
the rpm range from 3000 to 5500 rpm, after that switch off the engine
and let it cool down for 10 minutes.
2. Turn on the engine and let it run at the ground for 15 minutes varying
the rpm range from 3000 to 6000 rpm, after that switch off the engine at
let it cool down for 15 minutes.

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3. Turn on the engine and let it run at the ground for 15 minutes varying
the rpm range from 3000 to 6500 rpm, after that switch off the engine at
let it cool down.
The throttle must be continually opened and closed, so to vary the
amount of fuel/oil mixture that lubricates all parts.
At this point, you can fly the engine normally, having care to warm it up to
0/100 C° before take-off.
For the first 5/6 hours of flight, fly the engine with cautions.
NEVER FLY T E ENGINE AT FULL T ROTTLE FOR A LONG TIME.
The engine running-in is finished, respect your engine and it will become your
trustworthy partner in flight.
CARBURETOR
Your Black Bull is equipped with a Tryton carburettor, specially adapted for
the Cors-Air engines;
It is a top quality membrane carburettor, 100% made in Italy, that grants an
optimal performance, with decreased consumption and a better atomization
of the mixture fuel/air.
It is more sensitive to setting adjustments, and it is suggested for a
competition use, or for pilots skilled in mechanics who want the best results.
CARBURETOR
SETTINGS
BLACK BULL engine
( all configurations)
L screw 30/35 minutes
H screw 2 hours + 10 minutes

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MAINTENANCE
 AFTER THE FIRST HOUR OF RUNNING, CHECK THE BELT
TENSIONING, AND IN CASE RE-TENSIONING IT AT 380/400 z
 AFTER THE FIRST 2 HOURS, TIGHTEN HEAD NUTS (IN CROSS
ORDER) WITH A TORQUE WRENCH AT 2.5 Kg.m (25Nm).
 AFTER THE FIRST 3 HOURS OF ENGINE RUNNING MAKE A NEW
BELT CHECK UP AND IN CASE RETENSIONING IT.
Please note that if you find black dust inside pinion and/or rubber inside
pinion’s groove, it means that belt is not well tensioned and need to be
tightened.
Every 20 hours check:
 The condition and gap (0,7 mm) of the spark plug electrode
 Clean the air-filter, in case you have a fuel filter before carburetor, clean
it also.
 The torque of every bolt
 The tension and condition of the reduction belt
 Fuel lines and wiring
 That the cord of the starter has no abrasions
Every 50 hours check:
 Same controls of the 20 hours and furthermore
 The torque of the engine’s crankcase nuts
 Change spark plug
 Change the petals of the reed valve
 The reduction belt and the play of the pulley and change them in case
of need
 The condition of the starter gears (version with electric start)
 Once a year (independently from flight hours) change the diaphragm of
the carburettor