Roto 125 FS User manual

TOP FOUR STROKE ENGINES
ROTO 125 FS
OPERATING INSTRUCTIONS
OPERATING INSTRUCTIONS

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
ROTOmotor manufacturer of top four-stroke engines Page:2
CONTENTS
1. Introduction .................................................. 3
2. Safety instructions .......................................... 3
3. Package contents ........................................... 4
4. Mounting ..................................................... 5
4.1 The engine mount ...................................... 5
4.2 The engine ............................................. 5
4.3 Carburetor .............................................. 6
4.4 Fuel system ............................................ 6
4.5 Waste output ........................................... 7
4.6 Exhaust pipes .......................................... 7
4.7 Propeller installation .................................... 8
5 Ignition ...................................................... 10
5.1 Ignition installation .................................... 10
5.2 Ignition power supply .................................. 10
6 Engine lubrication ............................................11
7 Settings ...................................................... 12
7.1 The valves adjustment ................................. 12
7.2 Carburetor settings .................................... 14
8 Starting the engine ......................................... 15
9 Spare parts .................................................. 16
10 Accessories ................................................. 17
11 Warranty card ............................................... 18
12 Contact / technical support
VERSION 2.6/ENG
Please check the updates of the operating instructions on the website www.rotomotor.cz so that your engine always has the best care.

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
ROTOmotor manufacturer of top four-stroke engines Page:3
Thank yOu FOR chOOSing OuR pROducT
FOuR-STROke engine
pROduced in The czech Republic.
Introduction
You have purchased a new four-stroke two-cylinder petrol engine that requires the rst few
important steps to successfully start your RC plane model .
The engine has already been tested and started by the manufacturer, everything is ne and
it works as it should!
The engine is basically adjusted and tested with a 28/10 propeller tting and ROTO FS
exhausts.
• Always be very careful when handling the engine.
• The engine can start even when the propeller rotates very slowly and injure you!
• Whenever you start the engine, make sure that you have the model secured so that
there is no movement of the model and possible injury!
• Do not drive the plane with the engine running in between spectators and colleagues
at the airport!
• Do not touch the engine after the ight, it is hot and there is a risk of burns!
• You have one body, take care of it and enjoy ROTO engines.
1.
Safety instructions2.
ADVICE WARNING

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
ROTOmotor manufacturer of top four-stroke engines Page:4
Please follow the instructions carefully.
Check that all the listed parts are in the box.
Standard package contents:
1. ROTO 125 FS................................ 1 x
2. Ignition ROTO 125 FS....................... 1 x
3. Exhaust pipes .............................2 x
4. Waste oil hose ............................. 1 x
5. Spark plug key CM6 ........................ 1 x
6. Cable ties ..................................4 x
7. Silicone tubes .............................2 x
Package contents3.

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
ROTOmotor manufacturer of top four-stroke engines Page:5
Mounting
4.1 The engine mount
After mounting the engine firewall
occasionally to prevent loosening.
4.2 The engine
It is necessary to provide enough air for the supply to the carburetor. In case of lack of a air, the
engine may have poor performance and may uctuate at maximum speed.
It is necessary to ensure sucient cooling of the cylinder heads and cylinders with a constant
supply of air from the propeller or from the surrounding environment.
To mount the engine in the model, we will use steel strength bolts and lock nuts.
We will use large washers under the nuts due to the pressure distribution on the engine mount,
so that mount is not dented.
For the engine to work properly and its properties to be optimal, the engine must be warmed
up to operating temperature.
The carburettor is set at the factory (ROTOmotor). We do not recommend any disassembly of
the intake manifold or carburetor.
4.

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
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4.3 Carburetor
Do not remove the nozzle, do not modify it!
It‘s part of the engine, and the correct
operation of the engine depends on it.
A suction nozzle is mounted on the carburettor. We must ensure a sucient air supply for the
correct operation of the engine. Do not cover it!
4.4 Fuel system
It is necessary to connect a hose with fuel supply to the carburettor. A protective plug is atta-
ched to the carburettor fuel tting due to dirt during transport. This plug must be removed
and the gas supply from the model‘s tank connected in its place.
When removing the engine from the model for a longer period of time, it is necessary
to replace the protective plug to prevent the fuel in the carburetor from drying out.
The image is for illustration purposes only

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
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4.5 Waste output
NO TOOLS ONLY HAND LOCTITE 326
Then install the lubrication waste oil hose on the rear cover of the engine. To seal it we use
Loctite 326 glue or similar to seal the thread.
WAIT
3HOURS
We recommend leading the waste oil hose to the landing gear.
Waste output is very important and must never be blocked.
In any case do not reduce the diameter of the hose, or it will damage the engine.
If the waste output was clogged, the motor will be damaged.

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
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4.6 Exhaust pipes
The exhaust pipes are made so that they can be rotated around the axis. Therefore, set the
exhaust pipes to the desired position by turning and then secure by tightening the nut.
The exhaust pipes can be
rotated in a small range as
needed.
*A part of the package
± 10°
Beware of damage to the end of the pipe!
The end of the pipe serves as a sealing surface for the
extension tube. If damaged, it will not be possible to
seal the pipes correctly!
The diameter of the exhaust
pipe cannot be reduced!
Silicone pipes* are used to seal the transition between the exhaust pipes and the ROTO
exhausts, or between the extension pipe and the ROTO FS exhaust.
ROTO extension pipe and exhaust not included!
When mounting on the extension pipe or exhaust, the silicone pipe* must be secured with
a cable tie* on each side of the hose to seal the connection well.
There should be no more than 2mm
between the end of the exhaust pipe
and the exhaust.
The silicone pipe seals correctly only if the con-
tact surfaces are clean and free of grease.
When reassembling, the contact surfaces must
be degreased!

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
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4.7 Propeller installation
It is very important to mount the propeller correctly. 6 strength screws are used for this
purpose. Tighten them evenly! The propeller must be regularly checked and tightened, espe-
cially when using a new wooden propeller.
Check the tightening of the propeller often, especially at beginning, when the
propeller is new!
Loose screws will cause the screws cuts to, exposing you to the risk of injury
as well as damage to your model. This danger is mainly posed by the use of a
wooden propeller.
Direction of rotation of the propeller / Engine

ROTOmotor Ltd., Czech Republic - Europe ROTO 125 FS ROTOmotor Ltd., Czech Republic - Europe Operating instructions
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Ignition
5.1 Ignition installation
Never remove the Hall sensors from the backplate.
5.2 Ignition power supply
The recommended power supply for ignition is 4-9V.
Always charge the batteries before ying.
Do not rely on charging from the last ight!
Ignition installation is an integral part of installing an engine in an aircraft.
Place the ignition in a suitable place where there is no risk of excessive heat from the
cylinder heads or the exhaust system.
If the ignition is heated above 60 °C, the ignition will switched off and the engine stops
working.
Make sure that the ignition is
well and suciently cooled!
Make sure that the connectors are
tted correctly and that there is no
risk of loosening them!
Do not bend the HV cables into sharp
bends, they may be interrupted!
Install the spark plug cup from the ignition to the spark plugs.
5.