A) Engine Fine Tuning - Reely RAMBO Racing 7.5 RTR Bedienungsanleitung

6. Set-Up
a) Engine fine tuning
After the run-in phase of the engine, you can start the fine tuning to increase the performance.
To that effect, optimize the mix preparation for idle speed and change-over at the idle speed mix adjusting screw and with full throttle at the main noz-
zle needle.
This fine tuning is significantly simplified thanks to the carburettor of a new type with the material combination aluminum/plastic.
Carburettors made of metal only heat up a lot during operation which causes fuel parts to evaporate already in the carburettor.
Thus, the carburettor setting selected with a cold engine does not remain constant during operation.
The small heat absorption of the synthetic material prevents this effect.
Adjust the main nozzle needle (full throttle mix)
- Start the engine and remove the plug connector. Let the engine warm up for approximately 1 min.
- Drive the model as usual. If it seems that the engine runs too rich, make the mix leaner by screwing in the main nozzle needle by 1/16 rotations
respectively, until the desired setting is reached.
- Make sure that the mix is not too lean.
A light white trail of smoke should always be visible coming out of the exhaust pipe.
For an even increased performance, you can change to a fuel with up to 30% nitromethane
.However, there is the danger that the engine would show no satisfactory road performance any more, if you go back to a fuel
with a lower percentage of nitromethane.
If you want to use a fuel with a high percentage of nitromethan continuously, we recommend however, that you replace the
present cylinder head washer with a 0.1 mm (thicker) washer, in order to reduce compression.
If you do not reduce the compression, an overheating of the engine and a defective run can be the consequences!
Adjusting the idle speed mix adjusting screw
- Start the engine and adjust the main nozzle needle, as described above.
- Reduce the speed until the centrifugal clutch does not engage any more and that the wheels do not turn any more
when you lift the model off the ground.
- Let the engine cool down in idle speed for approximately 10 – 15 seconds.
- While you are holding the model with your hand, drive at full throttle once briefly and strongly.
Make sure not to touch moving parts!
- If the engine stalls as soon as you run at full throttle, then the idle speed mix is too lean.
- Enrich the mix by unscrewing the screw by 1/16 rotations while the engine is switched off.
- Restart the engine and repeat the procedure until the speed transition from idle speed to full throttle is effected softly and spontaneously.
A small delay in response is normal.
- If the engine smokes strongly during transition from idle speed to full throttle and sounds very rough, then the mix is too rich.
- Make the mix leaner by screwing in the screw by 1/16 rotations while the engine is switched off.
- Restart the engine and repeat the procedure until the speed transition from idle speed to full throttle is effected softly and spontaneously.
A small delay in response is normal.
- Drive the engine as usual in order to get a feeling of how the engine reacts to load changes.
- Modify the setting until the performance characteristics correspond to your expectations.
Once you have carried out these settings, a readjustment of the throttle stop is however necessary.
Adjusting the idle speed adjusting screw
The idle speed adjusting screw regulates the idle speed via the position of the slide carburetor (choke limit stop). The bigger the carburetor
outlet, the higher the speed.
Turn the screw clockwise in order to make the mix "leaner" (to reduce the proportion of fuel) and anticlockwise, if the mix should be "richer".
Depending on fuel, glow plug used and environmental conditions, small modifications in the settings might be necessary.
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Operating Instructions 4WD GP BUGGY RAMBO RACING 7,54 RtR No. 3 51 85