Thank you for buying a CMB - engine!
You have got one of the most innovative, powerful and long living engines.
We suggest to respect the following hints in order to get the satisfaction of fun and success for a long time:
1. Use the same content of Nitromethane with the fuel you will use in the future also
for breaking -in.
The engines will take fuels up to 30% of Nitromethane.
WARNING: Fuels containing more than 50% of Nitromethane will cause
short engine and glow-plug life! The fuels you use should not contain more
than 12% of oil. Take care that a minimum of 4-5% Castor - oil
(resin free,
CASTROL M for example) is a component of the mixture. We recommend the use of a
Quality - fuel mix being available from well - know producers. "Cheap fuels" are
not bad in general, but sometimes do not contain the ingredients for a long life of
the engine.
2. Tests as well as customers confirmation, the CMB engines are supplied clean and free from metal debris. Therefore do not open the engine before use. With this you can prevent that dirt is entering the engine! If you are used to clean the engine, before use and do not want to change this, kindly use clean Petroleum/Paraffin - oil and rinse the engine while carburetor and glow-plug are taken from the engine. (WARNING: Do not use brake - cleaner or other corrosive causing fluids!)
3. The carburetor has been set in standard modus in the factory. Eventually a
correction is necessary. In this case take care the engine never runs in a too lean
modus what will result in too much heat and a short lifetime! The most important
needle on the carburetor is the idle - needle. Those is the one you find horizontally mounted. Those always should be set tending to a
little bit of
a rich mixture. If you feel the idle-mix screw can be turned too easy, change the set-screw
(beyond the ball ) against a 6mm M3-hexagonal one. The much you tighten those,
the stronger the idle-mix-screw can be turned. |
Attention: Tighten the spray -
bar of the main-needle with care: Too much can brake it!
The boost-bottle should be mounted in a cool place. The stiffening-bar of the rear diff-box is a good mounting point.
4. Now you can mount the engine on the chassis of your car. (Before you do this
put the engine together with the mounting blocs on a flat glass - a mirror for
example) to check the bottom surface flatness. If this is not correct, the crankcase of
the engine may been bend when mounted, what can cause contact between
the crankcase and the crankshaft!
Now put the car on the start-box and start
the engine. (eventually the idling - screw - this is the black one left on the top of
the idling - needle - has to be adjusted) Is the engine running in a rich modus?
O.K. Let the engine warm up for 1-2 min. The "tapered' (intelligent) piston now fitted with all CMB - Car engines, avoids thermal problems however needs some time and oil for a perfect fitting to the cylinder! Now let the car go on the track. Do not use the full throttle for the first filling of the tank and change the revving from time to time. You than can carefully turn the main - needle to a leaner modus. Always care for a rich setting of the idle-mix -needle. Contrary to engines of other make, the CMB-engines need a rich setting of those for the development of their excellent running-behavior! The warmer the engine becomes, the smoother the sound will be.
Check the temperature of the engine by touching the head with a wet finger, better is
the use of special thermometers. The temperature should be in the range of 90-to
max. 110 Centigrade Celsius. (Not Fahrenheit! )
If you change the setting of the carburetor take care that this is done with the warm engine only!
If everything is right with the setting, the top of the piston as well as the glow-plug shows a light brown color. Let the engine idle for 30 sec. after use and do not cut It immediately. So you provide for the film of oil on the piston will take care for a tight fitting to the cylinder what makes a new start easy.
WARNING A too lean setting of the carburetor results in a very short life of the glow- plug and fast wear of the main - bearing!
