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Switching off the engine
Cut off the air supply to the carburettor. For this purpose, proceed as follows:
• Close the exhaust pipe with an engine stopper (or use a cloth instead) or stop the flywheel of the engine on the underside of the chassis using protective
gloves.
The fuel supply must not be disconnected as otherwise the engine might overheat.
n) Run-in instructions for the engine
The following must be observed during the run-in phase:
• Low engine speed
• Rich fuel-air mixture
• Short running periods and cooling-down periods (approx. 3 minutes each)
• Run-in time (mere engine running time) totalling approx. 45 minutes
Fuel:
The addition of nitromethane to the model fuel increases the ignitability of the fuel and consequently the performance of the engine. In the run-in phase, use a
model fuel with a small content of nitromethane in order to avoid overheating of the engine. The fuel should also have a higher percentage of oil ("rich"
carburettor setting) so that the lubrication of the engine is improved until piston and cylinder liner are run in.
After filling in the fuel and starting the engine as described above, you can start running in the engine.
The wheels must be hanging freely in the air! Put the model on a car stand or similar and carry out the first run-in phase with the model in a fixed
position!
In order to be able to use the full power spectrum later on, the engine should have two to four tank fillings at a "rich" carburettor setting and run with
changing throttle. This is indicated by the thick white production of smoke from the exhaust pipe.
1st run-in phase:
• After each engine operation (tank filling), allow for a sufficient cooling-down phase. Afterwards, the mixture can be made leaner by screwing in the main jet
needle gradually.
• Leave the glow plug starter inserted and let the engine warm up for approximately 1 minute without accelerating. If necessary, unscrew the main jet needle a
little (the flow rate is increased).
• Remove the glow plug starter after a one-minute warming-up phase.
• Let the engine run for about 2 - 3 minutes with cooling-down phases in between. Increase the speed only slightly with short throttle bursts.
The engine runs very roughly and the model does not run smoothly.
• Turn off the engine after 2 - 3 minutes and allow it to cool down for about 10 minutes.
2nd run-in phase:
• Make the engine settings a little leaner by turning in the main jet needle a 1/8 revolution. Restart the engine.
• Leave the engine running for another 2 - 3 minutes with cooling-down phases in between. Now the engine should accept the throttle a little better, but there is
still smoke.
If the engine starts turning quickly only briefly and then stalls, unscrew the main jet needle a little again.
• Turn off the engine again and allow it to cool down for about 10 minutes.
• Repeat this procedure and make the mix slightly leaner each time.
3rd run-in phase:
The vehicle can now be run at a slow speed (max. 1/2 throttle) for three more tanks of fuel.
Too lean a mix causes overheating and engine seizure. For a long engine life you should prefer a slightly rich carburettor setting and a fuel with a sufficient
percentage of oil (16%).
The total driving time (engine running time) should be approximately 45 minutes. After this time, the engine should be run in. You know that the engine is run in
when it can be cranked up in cold state without a spark plug and without noticeable resistance.
Now you can operate the engine at full power.
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