Radne Raket 120 User manual

Radne Motor AB
User
Manual
English

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© Radne Motor AB 1998-2010
Introduction
Congratulations to your choice of engine. The Raket 120 is a multi purpose engine, which you will nd useful
for many applications. If you read this manual before you install and start your new engine you can avoid some
costly mistakes.
Keep this manual as a reference, it is a part of the complete delivery from Radne Motor AB in Sweden or our
distributors.
Read carefully the safety precautions on page 5.
If you, after having read this manual, have more questions about the Raket 120 engine or the installation of it for
any particular application, you are always welcome to contact Radne Motor or our local distributor. We want to
make sure that every product we produce and sell will meet the expectations of our customers.
Information when contacting us:
Radne Motor AB
Box 3035
S-136 03 Haninge
Sweden
phone: [phone]
fax: [phone]
e-mail: [email protected]
home page: www.radne.se and www.raketengines.com
Rev 3, 2010-01-02

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Radne Motor AB
Radne Motor AB was founded in 1967 by Leif Radne to manufacture and
sell parts for gokart racing. Approx. thirty years later this is still the business
idea of the company, and it is still led by Leif Radne. Radne Motor is today
the leading Nordic gokart business. Radne Motor represents the leading
manufacturers of tyres, chassis and personal protection, and is also produ-
cing the Raket line of engines, mainly for gokart use.
In Sweden, Radne Motor is well-known for very good service. Orders are
normally shipped the same day as they arrive. The repair and service of
engines and karts is done in one of the most modern kart service shops in
Europe. Radne Motor is also present at most gokart racing tracks in Swe-
den, either through distributors or from the Radne service and spare parts
van.
Over the years, more than 25.000 Raket gokart engines have been produ-
ced. They form today the basis for many classes for young drivers. Raket
engines are used for racing, for rental karting or just for karting-for-fun. For
whatever purpose, its owner always appreciates the extreme durability of
the Raket engine.
Radne Motor has distributors in 25 countries abroad, so it is very likely that
you will nd one also in your country. Ask for a list of distributors. But, you
can also order products and parts directly from Radne Motor. Customers
abroad nd it very convenient to order engines and parts via Internet, our
home page is: www.radne.se
Radne Motor publishes every year a new catalogue with all the parts we
sell. The catalogue also contains complete spare parts lists for most of the
products we sell. In many countries Radne Motor has issued homologation
forms that describe in detail all critical measures for the Raket engines.
These forms are available from the national automobile sport federations.

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Raket engines
The rst Raket engine was introduced in 1972. Extensive research for a
reliable, simple to use, yet fun to drive gokart engine at an acceptable price,
had convinced Radne Motor to start the manufacture of such an engine.
Power chain saw engines are the toughest two stroke engines that are
built, and Radne Motor decided to build the gokart engine on well-tested
vital parts. Hence, cylinder and piston, crankshaft, carburettor and ignition
system were purchased. Radne Motor manufactured other parts that are
typical for a gokart engine, like the aluminium crankcase. Finally, the engine
was assembled and tested by Radne Motor before it was shipped. All Raket
engines have been built around this concept, which has proven to be very
successful.
Today the Raket line of engines consist of:
Raket 60 for the very young drivers. This engine has rope start, centrifugal
clutch and forced air cooling. It can be equipped with catalytic emission
control and a rev. limiter.
Raket 85 is the most popular and most produced Raket engine. It is used
in many countries for the youngest drivers. Often the same engine is used
with some type of power restrictor for the youngest, and later, with the
restrictor removed, for the more professional drivers. The Raket 85 engine
has a whole series of extras and conversion kits, so it can be used also for
indoor driving and for rental kart use.
Raket 120 is used mainly for Ultra Light Aircraft, so called Para-gliders. This
engine is extremely powerful for its low weight. But Raket 120 has found
many more uses, both for gokart and where the low weight in combination
with high power and good reliability is appreciated.
Spare parts and service for the Raket engines are available from Radne
Motor or from our distributors. We recommend that you consult our catalo-
gue. A new catalogue is produced every year, in which you nd the latest
parts and also hints for the best use of your Raket engine.
Raket 60
Raket 85 Racing
Raket 120 Racing ES
Raket 95
Raket 120 Aero ES
Raket 120 ES-RD

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Safety precautions
The Raket 120 engine is intrinsically a very safe design. If you follow these
rules and general rules for machine safety, you should not encounter any
risks or hazards.
1.Always equip your engine installation with a safety switch, which will make
emergency stop possible from where the engine is normally operated.
2.Always protect rotating parts with protective covers.
3.Never machine any rotating parts. It is explicitly forbidden to machine the
ywheel or the clutch drum, as machining can cause them to explode.
4.Take care when you handle gasoline. It can ignite if exposed to heat or
ame. Always stop the engine when you ll up with gasoline.
5.Cylinder and mufer become very hot, and you must protect yourself and
other persons from accidental contact with hot parts. Also after the engine
has been stopped, those parts remain hot for quite some time. NOTE! If
your engine is equipped with catalytic emission control, the temperature
of the catalytic converter is extremely high, also a long time after you have
stopped the engine. Make sure that any contact with the mufer and the
catalytic converter is impossible.
6.The exhaust fumes are poisonous and contain carbon mono oxide. Never
run your engine in a conned environment. Make sure that neither you nor
any other person is exposed to the fumes from the running engine.

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Main component Learn about Page
1 Crankcase, engine stand Assembly of engine in chassi or frame 8
2 Carburettor How to set the jets 9
3 Ignition Electrical settings 12 4
4 Spark plug Nippondenso W22MP-U 12
5 Decompression valve How to start 12
6 Magnapul start How to change rope 13
7 Clutch How to maintain the clutch 14
8 Cylinder and piston Maintenance hints 15
9 Crankshaft Service hints 15
10 Mufers Different types and how to install them 15
11 Wearparts When to change them 16
12 Preparations for start 17
13 Problems? How to solve them 18
Make yourself familiar with the Raket 120 engine
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(Other side)
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How to install the Raket 120 engine in a
chassis or frame
For the assembly of the Raket 120 engine four threaded holes, M8, are
provided in the bottom of the crankcase. For mounting the engine in a kart,
a special mounting plate is available (part No 3004) with mounting clamps
(part No 3005), which facilitates the assembly as well as the adjustment of
the chain tension.
Note, the correct length of the M8 bolt is important. The depth of the th-
readed hole is 20 mm. You should make sure that, when fully inserted in the
hole, the bolt uses at least 18 mm of the treaded hole, but also that the bolt
is not too long to penetrate into the crankcase.
For mounting the engine in a ULA, the specics for each ULA will determine
the best mounting procedure.
The crankcase and the cover over the rope starter are made of aluminium.
You must protect all rotating parts for two reasons. First is to prevent you or
another person to come in contact with a chain or shaft where you can get
caught and be injured. Secondly, because of the high speed of the engine
(up to 15.000 rpm) very big forces are present. If a chain or shaft should
break, you must be protected against parts that can be thrown away. If you
feel uncertain about the design of these protections, you should consult
someone for professional help.
After you have mounted the engine to the frame or structure, you must
make the following connections:
·connect the fuel tank with the carburettor inlet nipple
·connect the accelerator pedal or equivalent with the throttle of the carburet-
tor
·connect the emergency breaker
These are all the connections needed.

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The carburettor
The Raket 120 is equipped with a Walbro diaphragm
carburettor of type VG6 with xed High Speed jet.
How it works
The carburettor is connected to the fuel tank with a exible
hose, made of rubber or plastic. The hose connects to the
fuel inlet nipple (part No 32029 - see gure).
When you pull the starter rope and the piston moves up and
down the cylinder, the pressure variations in the crankcase makes the
pump diaphragm (part No 32045) move up and down. As the outer side of
the diaphragm is connected to the fuel inlet nipple via two rubber valves, the
movement of the diaphragm will cause a pumping action that will draw fuel
from the tank to the carburettor.
NOTE! The tank and the engine shall be placed so that the carburettor
normally shall suck fuel from the tank, i.e. the fuel shall not ow freely from
the tank to the carburettor causing an over-pressure. Neither shall the tank
be placed so low that the pump of the carburettor has difculties in pumping
the fuel from the tank.
NOTE! During normal operation the carburettor shall pump air free fuel
from the tank. If, due to heavy vibrations or excessive movements of the
fuel tank, you can observe that the fuel is mixed with bubbles of air (use a
transparent plastic hose), this may cause the engine to loose power or to
stop. If this problem cannot be solved by changing the mounting of the fuel
tank, you may try to equip the fuel take off in the tank with a fuel pick up.
Fuel pick ups are normally used in power chain saws, and may be obtained
from most chain saw service stations.
After the fuel has passed the pump it reaches the inlet valve (sometimes
referred to as the inlet needle valve - part No 32025). The normal position
for the valve is closed. The valve can be opened only if the main diaphragm
(part No 32017) is pressing down the lever (part No 32024). It is the amount
of fuel in the main chamber that makes the main diaphragm move. When
the valve is open, the fuel will ow into the main fuel chamber of the car-
burettor. From the main chamber the fuel can ow into the venturi of the
carburettor through two jets. One jet is xed, and controls the ow of fuel
at high speed. The size of this jet is factory set and shall not be changed. If
you change the xed jet to another size you will either loose some power or
your engine will run too lean and seize up.
The second jet is adjustable, it is a needle valve. It controls the ow of fuel
at low speed. The normal setting of this needle valve is one turn open from
its closed position. Before you make any attempts to start the engine, make
sure that the needle valve is in the ”one turn open” position. Later you may
open it a little further to make your engine run a little richer, or close it to
make the engine run leaner.
NOTE, never set the low speed valve less than ¾ of a turn open, as leaner
settings may cause severe engine problems.
The carburettor is equipped with a cold start device, sometimes referred to

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as the choke. The purpose of the choke is to enrich the fuel during start by
restricting the air ow and increasing the vacuum in the venturi. When you
intend to start your Raket engine, you normally close the choke and pull the
starter rope. After one or two pulls the engine will start. As the fuel-mixture
with closed choke is very rich, the engine will normally stop soon. Then you
open the choke, open the throttle a little and pull the starter again. Now the
engine shall normally start on the rst pull and run smoothly.
Installation
Apart from connecting the carburettor to the fuel tank, you also connect
the lever of the throttle shaft to your accelerator pedal or other device that
controls the speed of the engine. Note that on the carburettor there is an
idle speed adjustment screw that allows you to set the rpm when the engine
idles. The correct setting is found in combination with the setting of the
low speed needle valve. When idling you shall be able to open the throttle
without any tendencies for the engine to stop or stall. When you make this
adjustment you normally let the engine run at a speed a little over the nor-
mal idle speed by turning the inlet speed adjustment screw a little clockwi-
se. Adjust the low speed needle valve so that the engine responds directly
when the throttle is opened, both slowly and quickly. When you have found
the best setting, turn the low speed adjustment screw counter clockwise
until the correct idle speed is found.
Service
Actually, there isn’t much that can go wrong. If your fuel mixture is clean so
no deposits clog up the interior of the carburettor you will have a problem
free operation. We recommend you to change the two diaphragms and the
gaskets once every year. If you haven’t used your engine for some time, the
diaphragms may have hardened and you may change them if you notice
the engine is more difcult to start or it doesn’t run smoothly at low rpms.
If you are troubled with unstable operation, i.e. sometimes the engine stops
at idle speed, sometimes it revs up and you have to adjust the setting of
the low speed needle valve. Then, it may be the inlet needle valve that is
causing you problems, and we recommend you to change the inlet needle
valve (part No 32025).
NOTE. If you nd that you have problems with deposits in the interior of
your carburettor due to contaminated fuel, we recommend you to install a
small fuel lter in the hose between the tank and the carburettor.
If none of the hints above solve your problems, and you still have problems
with low power or unstable idle speed, check the condition of all gaskets in
the carburettor and between the carburettor, heat shield (part No 32065)
and the cylinder. If this doesn’t solve your problems, we recommend you to
disassemble the carburettor from the engine and have it cleaned by Radne
Motor or one of our service agents. You may also nd professional help at a
service station for power chain saws, snowmobiles or garden tools.

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Air lter
It is strongly recommended that the Raket 120 engine is equipped with an
air lter. Radne Motor has a number of different designs which all protect
the interior of the engine from being damaged by sand, dust and other hard
particles. See main catalogue, i.e. inlet silencer No 5201.
·the inlet noise is drastically reduced, resulting in total engine noise reduc-
tion
·improved lter action, prolongs engine life length
·protects the engine during rainy operations from being ooded with water
·can improve the engine torque curve at low speeds (depending on inlet
silencer and output mufer arrangement - please contact Radne Motor for
advice)