Switching off the engine
For this purpose, proceed as follows:
• Cover the exhaust with a motor stopper (alternatively a rag) or stop the flywheel of the engine on the bottom of the chassis while wearing gloves.
The fuel supply should not be disconnected, or the engine may overheat.
j) Break-in Instructions for the Engine
The following must be observed during initial break-in:
• Low rotation speed
• Rich fuel-air mixture
• Short running times with cool-down stages (approx. 3 min. each)
• Run-in time (real engine runtime) totalling approx. 45 minutes
Fuel:
The addition of nitro methane to the model fuel increases the ignitability of the fuel and thereby the performance of the engine. In the running in stage, use a
model fuel with a small addition of nitro methane in order to avoid overheating 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 having filled in the fuel and started the engine as described above, you can start running in the engine.
The wheels must be freely suspended in the air! Place the model e.g. on a car stand and perform the first run-in stage while the model stands still!
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 strong white smoke emission from the exhaust pipe.
1. Initial break-in stage (2 tank fillings)
• After each engine running (tank filling), allow for a sufficient cooling stage. Afterwards, the mix can be made leaner by screwing in the main nozzle needle step
by step.
• Leave the glow plug connector attached and let the engine warm up for approximately 1 minute without accelerating. If necessary, unscrew the main nozzle
needle a little (the flow rate will be bigger)
• Remove the glow plug connector after a one minute of warming up stage.
• Let the engine run for about 2 – 3 minutes with cooling down stages in between. Increase the speed slightly with short throttle bursts.
The engine runs very roughly and the model moves very reluctantly.
• Shut the engine off after 2 - 3 minutes and let it cool down for approx. 10 min.
2. Initial break-in stage (2 tank fillings)
• Set the engine slightly "leaner" by twisting the main nozzle needle in by 1/8 of a turn and then start it again.
• Let the engine run again for about 2 – 3 minutes with cooling down stages in between. Now the engine should accept the throttle a little better, but there is still
smoke.
If the engine revs up briefly and then stalls, unscrew the main nozzle needle slightly once more.
• Turn the motor off and leave it to cool down for 10 min. again.
• Repeat this procedure and make the mix slightly leaner each time.
3. Initial break-in stage
For three more tank fillings the vehicle can now be run at a slow speed (max. 1/2 throttle).
A mix that is too lean causes overheating and engine seizure. For a long engine life you should prefer a slightly rich carburettor setting and fuel with a sufficient
percentage of oil (min. 16%) is best.
Overall, the real driving time (engine run time) should be approximately 45 minutes. After this time, the engine should be run in. You can tell that the engine is run
in when it can be cranked up in cold state without spark plug and without noticeable resistance.
Now you may operate the engine with full power.
Always make sure that the carburettor adjustment is set to a sufficiently rich mode (a slight trail of smoke from the exhaust pipe must be visible) in
order to avoid overheating, increased abrasive wear or engine damage.
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