Nosram RR.21 X-treme Manual De Usuario

MA00238
USER GUIDE
NOSRAM RR.21 X-treme
# 94251
2.92 HP
40.000 RPM
for distributor address see packaging
1. SPECIFICATION
Engine size
Exhaust
Bore
Stroke
Liner
Number of ports
Main bearing
Crankshaft 14.0mm / DLC coating / precision balanced / with silicone insert
Crankcase
Piston
Connecting Rod
Glowplug
Carburetor
Power Output*
Max. RPM*
Weight
*Figures may vary depending on used fuel, exhaust system and tuning.
2. FUEL
Never use regular gasoline or airplane fuel. Use fresh 2-stroke model car fuel only! We recommend
using our line of NOSRAM fuels. For the NOSRAM RR.21 X-treme engine, we recommend a fuel with
25% nitro. Never exceed 36% nitro. A higher nitro content will decrease your engine's lifetime.
3. AIRFILTER
A good airfilter is very important for the life of your engine. Never run without an airfilter, as quick
and permanent damage will result! Don't forget to impregnate the airfilter with a suitable oil before
usage. Carefully clean the airfilter at least after every tenth tank. Replace the airfilter every 3 litres
(~1 gallon) of usage.
4. GLOWPLUG
Use only Turbo style glow-plugs (also known as conical style plugs) for this engine. We recommend
using our line of high-quality NOSRAM Glowpluxx2 Turbo glowplugs (#94766 - #94786, availabe
as T3 to T5). Check them frequently and never run with worn-out or old glow-plugs since they could
damage your engine. They turn dull when your engine was too lean and should be replaced. They should
stay bright like chrome. If the glowplugs wear out too fast, an additional 0.1mm shim between burn-
room and liner is recommended. Whenever you have trouble with the engine stalling for no reason,
replace the glow-plug first!
TIP: Our NOSRAM race-team always uses a NOSRAM Glowpluxx2 Turbo T3 (#94766) plug for
the NOSRAM RR.21 X-treme engine.
5. EXHAUST SYSTEM
Never run without a pipe since this will cause excessive overheating and may damage your engine. A
good pipe has a very huge effect on the performance of a 2-stroke engine. For the NOSRAM RR.21 X-
treme engine, we recommend using our high-quality NOSRAM Twister 1/8th Buggy Exhaust System
(#94865) for maximum performance.
© NOSRAM 2012
www.nosram.com
.21 (3.49ccm)
Rear
16.30mm
16.80mm
ABC
3+1 (3x transfer-, 1x exhaust-port)
Ceramic
Black XTEC C6 .21 Heavy-Duty Competition
Specially lightened, high-silicium alloy
Oversized, knife-edge shaped, extra strong aluminium,
double bushings
hot WT3 turbo style included
hot WT3 or WT4 plugs recommended
XTEC thermal protected carburetor.
Aluminium 6.0, 6.5 and 7.0mm inserts included.
2.92 HP
40.000
345g
Dear Customer,
thank you for your trust in this NOSRAM product. By purchasing a NOSRAM nitro engine, you have
chosen a high-performance and highly sophisticated product, which doesn´t make any compromise
between maximum performance and easy tuneability. We hope you enjoy your new engine.
Please read the following instructions carefully before you start using your NOSRAM RR.21 X-treme engi-
ne. This user guide contains important notes for the installation, the safety, the use and the maintenance
of this product. Thus protecting yourself and avoid damages of the product.
Proceed according to the user guide in order to understand your NOSRAM RR.21 X-treme engine better.
Please take your time as you will have much more joy with your product if you know it exactly.
This user manual shall be kept in a safe place. If another customer is using this product, this manual has to
be handed out together with it.
6. HEAD CLEARANCE
We recommend a real head clearance between piston and burnroom of about 0.60-0.70mm (0.024-
0.027") or more, when the piston is at Top Dead Center. The real head clearance can be calculated
as follows:
Real head clearance = Thickness of head shims + 0.25mm*
We suggest to start with 0.35mm (0.014") shims underneath the combustion chamber. You may
want to adjust the shims depending on nitro-content (see table) or track layout. Large tracks may
require an extra 0.10mm (0.004") shim to reach higher topspeed and improved fuel consumption, but
this will decrease acceleration slightly.
Nitro content 16%
Real head clearance 0.60mm / 0.024"
Head shims 0.35mm / 0.014"
* (that's due to the internal construction of the engine and the compression of the head shims, when the cooling
head is mounted)
7. CARBURETOR
The factory settings of the engine are as following and are a good starting point for you, if you are not
satisfied with your carburetor settings. Turn in the needles completely (Caution: Do not overtighten
them!) and loosen them the required number of turns again:
• Main speed needle (#3): 3 1/4 turns
• Mid range needle (#2): 2 1/2 turns (starting from the needle being flush with the ball
link)
• Third needle (#4): Exactly flush with the carburetor body
Idle screw (#1):
Adjusts the air flow when carburetor is fully clo-
sed. Turn CW for higher idle-speed and CCW for
lower idle-speed. Should be open approx. 0.5mm.
Mid range needle (#2):
Adjusts the mid/low-speed flow rate of the fuel.
Turn CW for leaner and CCW for richer setting.
Main speed needle (#3):
Adjusts the main flow rate of the fuel (when the throttle is opened
significantly). Turn CW for leaner and CCW for richer setting.
Third needle (#4):
Should always stay in the factory setting exactly flush with the carburetor body and should not be
changed.
Carburetor venturi inserts:
In order to affect the fuel/air mixture, you can use different venturi inserts on this carburetor. These
are to finetune your engine to different track layouts. There are three different venturis coming with
the engine: 7.0mm, 6.5mm and 6.0mm.
- 7.0mm has the most power, 6.0mm has the best fuel mileage.
8. RUN-IN
Proper run-in of the engine is a very important step in ensuring that you get the highest performance
and lifetime of your engine. Take your time for proper run-in. Do not use run-in benches, but use your
car for run-in. Use the same fuel as you will be using for the life of the engine. Special run-in fuel is not
needed. If your engine doesn't start easily you may try loosen the glow-plug by ½-turn to decompress
the engine and try again. Don't forget to tighten the glow-plug again once the engine started!
Procedure:
• Start the engine and set the main-needle very rich, i.e. excessive smoke coming from the muff-
ler.
• Let the engine idle for 2mins first to warm it up.
• Now start driving your car, it will be slow and sluggish, but this is an important step.
• Do not allow the engine to rev-up too high, run the engine at half speed on the straightaway.
• The engine should not be too cold and not too hot during run-in, 70-80°C (160-180°F) is per-
fect.
• Let the engine cool down for 15mins after each tank during the run-in period.
• We recommend doing so for 5 tanks of fuel before you start tuning your engine.
20% 25% 30%
0.65mm / 0.025" 0.70mm / 0.027" 0.80mm / 0.031"
0.40mm / 0.015" 0.45mm / 0.016" 0.55mm / 0.022"
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