AvioMac 70cc Twin User manual

INSTRUCTION MANUAL AND ENGINE
WARRANTY.
70cc TWIN (IDM)
CODE: AV070B2B

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WWW.AVIOMAC.COM AVIOMAC 70 TWIN (IDM)
IMPORTANT!
Thank you for purchasing one Aviomac
70cc, one of the best gasoline engine
available. With our 3-year warranty on
manufacturing defects and costumer
support, we are sure that you will be glad
with this engine.
For customer who have had gasoline
engines before some information may not
be new, but we recommend you to follow
our instruction to have a safe and good
running engine for a long time.
Warning: Before starting attempt the
engine read the instruction manual
completely.
•This is not a toy, it is a high-quality,
powerful engine and it is safe, if it
is used properly.
•Make sure that when you start the
engine you are not wearing loose
clothing or you are not using things
that could catch the propellers or
the engine.
•Make sure that all people are
beyond the engine and out of the
propeller line.
•This engine was designed for
modelling aircraft, so do not use it
for other purpose.
•Do not start the engine if it is not
kept.
•It is important to use always
original spare parts and high-
quality accessories.
•We recommend you to install an
external switch and a servo
operated kill switch (not included).
•Do not pressurize the fuel tank, the
carburettor has a fuel pump that
take the necessary quantity of fuel
to allow right working.
•Never start the engine without
wearing leather glove or without an
electric starter.
PACKING LIST:
1 Aviomac engine 70cc Twin
2 Spark plugs
2 Spark plugs covers
1 AT coil
1 Ignition control box
1 Easy Starter
1 Carburettor
1 Instruction manual
2 Aviomac stickers.
INSTALLATION GUIDE
Here you will find some
recommendations. Read them before
install your engine:
1. To reduce possible RF
interference, we recommend to
maintain a 20-30 cm distance
between the engine and the
receiver, servos and the receiver
battery pack.
2. Always use steel screws with self-
looking nuts to ensure the engine
to the firewall.
3. Use a minimum 7mm firewall for
engine installation.
4. Check the tightening of screws
after first flight and periodically
every 5 flight hours.
5. We recommend to use nylon
pushrods, fibreglass or fibre wood
for attach the throttle linkage.
Metal pushrods could cause radio
interference or vibration inside the
engine.

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WWW.AVIOMAC.COM AVIOMAC 70 TWIN (IDM)
ENGINE MOUNTING
1. Engine has been designed to
being mounted with the carburettor
facing downward to avoid flooding.
2. The ignition is located on the rear
of the engine. If you need to place
the ignition control box behind the
firewall drill a 12mm hole in order
to feeding ignition wires through
the hole.
3. Mount the engine to the firewall
using only M6 steel screws, metal
washers and self-looking nuts.
4. It is recommended to mount coils
and ignition control box on elastic
supports, possibly behind the
firewall and far away from radio
components.
5. We recommend you to install two
different kill switches, one external
and one internal activated by a
servo. In this way you can switch
off the engine when it is on the
ground or when it is on flight in an
emergency. See the following
electric drawing for a correct
installation.
ADDITIONAL PARTS RECCOMENDED
FOR INSTALLATION (NOT INCLUDED):
1-elastic spacer for AT coil
1-elastic spacer for ignition system
2-M6x16 steel screws with self-looking
nuts.
60 cm of wire for kill switch and ground
strap.
1-external kill switch
1-servo internal kill switch
4-M6x25 screws complete of washers
and self-looking nuts
EASY STARTER INSTALLATION
The Easy Starter is an accessory that
allow an easier start of the engine. The
Easy Starter need 8 AA batteries (not
included and preferably rechargeable) for
power.
The engine can be started without Easy
Starter using an electric starter.
The Easy Starter connector installed on
the ignition control box can be fixed with
some screws to the firewall. It has to face
the external part of the plane in order to
communicate outside through a hole of
appropriate size. This will give you the
possibility to connect the Easy Starter
easily when you start the engine.

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WWW.AVIOMAC.COM AVIOMAC 70 TWIN (IDM)
FUEL
The engine works with a fuel-oil mixture
at a ratio of 4% (25:1). Example: 10 litres
of fuel and 0,4 litres of oil. Use always
fresh unleaded fuel and high-quality oil,
we recommend Shell Advance Racing oil.
Do not use old fuel or fuel that has been
stored for over 3 months.
CARBURETTOR SETTING
The carburettor has 2 needles for
carburation setting and one needle for
minimum setting. The needle marked with
a L enables low RPM, the needle marked
with a H enables high RPM, the needle
marked with IDLE serves to keep the
engine running at idle. Turning clockwise
L and H needles will lean the mixture
(less fuel), turning counter clockwise the
needles will rich the mixture (more fuel).
We recommend to start with this setting:
close completely the Hneedle and turns it
out of 1 turn, close completely the L
needle and turns it out of 1 turn and ½.
Do not try to adjust the needles with the
engine running because the propeller
could cause severe damage, so shut the
engine off before start setting the
carburation.
Gasoline carburettor are much sensitive
than GLOW carburettor, so they need
precise setting to allow the engine
working well. Avoid making more than 1/8
turn adjustment of carburation needles.
The third needle is the IDLE stop needle,
it serves for keep engine running at idle.
We suggest to screw it out to allow the
engine to be killed. The throttle has a
spring that allow it to return to idle. If you
want, you could release the spring to
avoid a constant load on the servo.
We recommend to maintain the spring on
its original position when you test the
engine on a work bench. Never remove
the spring from the carburettor.
PROPELLER:with Aviomac 70cc engine
we recommend propellers as following:
20x12, 22x10, 22x12, 24x10.
Propeller hub is designed to allow the
installation of 2 security screws. We
highly recommend installing these screw
to avoid dangerous falling of the
propeller.

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WWW.AVIOMAC.COM AVIOMAC 70 TWIN (IDM)
STARTING PROCEDURE
PRIMING
1. Before starting the engine, it is
useful a priming procedure. Make
sure that the AT coil is switched off
by activating the kill switch or
grounding the black/white wire.
2. With the ignition turn off, speed
up completely, close the coche
plate and swing the propeller
several time. This will draw fuel
into the carburettor. Continue
swinging until you see fuel drip out
of the carburettor.
CAUTION: do this procedure only
when the carburettor is facing
downward.
HAND STARTING
1. Connect the Easy Starter into
the connector of the ignition
control box. Press the button
on the Easy Starter and make
sure that the red LED lights.
2. Open the coche plate, speed
up slightly, deactivate the kill
switch and make sure that the
aircraft is restrained or
someone hold it. Flip the
propeller until the engine starts.
If the engine does not start,
repeat priming procedure until it
starts.
NOTE:Always turn the Easy Starter off
before you disconnect it from your
aircraft, otherwise electric shock and
damages on the ignition can occur.
ELECTRIC STARTER
If you use an electric starter, Easy Starter
is not necessary. Follow the same
starting procedure and of course do not
connect the Easy Starter.
CARBURATION
Let the engine warming up for first 30
seconds before tune or speed up. The
carburation begin with the tuning of low-
speed needle (L) and then it is followed
by the tuning of high-speed needle (H).
Low-speed needle adjustment: if the
engine coughs, the mixture is too rich, so
turning it in a 1/16 turn at a time until the
engine does not go better. If the engine
does not accelerate from the idle, the
mixture is too lean. Turning low-speed
needle out a 1/16 turn at a time.
High-speed needle adjustment (H):
After you have adjusted the low-speed
needle (L) is the moment to tune up the
high-speed needle (H). Speed up
completely. If the engine drops RPM it
means that your mixture is too rich.
Screw clockwise the high-speed needle
(H) for 1/16 turn at time until the engine
work well. Tune the high-speed needle
(H) to allow the engine to reach maximum
RPM, then turn it out until the engine
reduce by 50-100 RPM. This will
guarantee a carburation not too lean and
a longer life for the engine.
Recheck and eventually adjust the low-
speed needle adjustment (L).

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WWW.AVIOMAC.COM AVIOMAC 70 TWIN (IDM)
PROCEDURE FOR MAGNETIC IGNITION TUNING
All Aviomac engines are sent with ignition yet tuned up for work well, but after the
disassembly of the ignition and for all adjustment needing, you have to follow this
procedure:
1. Insert the rotor on the crankshaft; we remind you to use its positioning key and
block it with its screw (included in the shipment).
2. Position the comparator on the cylinder and take the piston to the Upper Dead
Centre (UDC).
3. Rotate the crankshaft counter clockwise and take the piston to 2mm before the
UDC.
4. Position the ignition as you see in the drawing.
5. Finally you have to block the stator with its 4 screws.

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WWW.AVIOMAC.COM AVIOMAC 70 TWIN (IDM)
WARRANTY
The engine has a 3-year warranty from
the date of purchase for material and
manufacturing defects. The warranty is
limited at the original purchaser and it
cannot be transferred.
The warranty does not cover:
1. Normal wear of the engine
2. Damage resulting from inadequate
maintenance
3. Damage resulting from
overrunning, caused by the loss of
one propeller or by using a
propeller too small.
4. Damage resulting from bad
carburation (too lean)
5. Damage resulting from a crash
6. Damage resulting from using not
original spark plugs
7. Damage resulting from using not
suitable fuel or oil
8. Damage resulting from outsider
objects that have got in the engine
9. Damage resulting from modifying
engine components.
10.Damage resulting from the
disassembly of the engine by non-
authorized staff.
11.Damage resulting from wrong
installation of the engine
12.Damage resulting from unfit using
of the engine
For warranty or non-warranty services,
you can send your engine with good
packing and with transport paid at the
following address:
MGR Group Srl
Via dell’Artigianato, 12
37060 Sona (VR) Italy
Phone number:++39-045-6095552
Together with the engine you have to add
your name, your address and your phone
number (or an email address) for a
possible contact and to return you the
engine. The engine has to be delivered
complete of ignition.
In case of non-warranty service, we will
contact the costumer to inform him about
cost and means of payment.
Do not send mufflers, propellers, fuel, oil
or accessories not included in the original
packing of the engine. Include a complete
written explanation of the problem and
setting used (propeller measure, brand
and mixture of oil and fuel, spark plugs
installed, etc.).
IMPORTANT:
The warranty will be valid only if the
warranty form is filled in all parts and it is
sent by fax, e-mail or postal mail within 10
days from the date of purchase.
Warranty will be valid for 3 year from the
purchase date, attested by the purchase
invoice or the receipt.
Please save original invoice or receipt :
the warranty will not be valid without
these documents.