User manual OS ENGINES MAX-12TZ

[. . . ] ENGINE Remember that your engine is not a "toy", but a highly efficient internalcombustion machine whose power is capable of harming you, or others, if it is misused. As owner, you, alone, are responsible for the safe operation of your engine, so act with discretion and care at all times. engine is acquired by another person, we would respectfully request that these instructions are also passed on to its new owner. The advice which follows is grouped under two headings according to the degree of damage or danger which might arise through misuse or neglect. WARNINGS These cover events which might involve serious (in extreme circumstances, even fatal) injury. 2 NOTES These cover the many other possibilities, generally less obvious sources of danger, but which, under certain circumstances, may also cause damage or injury. WARNINGS · Never touch, or allow any object to come into contact with, the rotating propeller and do not crouch over the engine when it is running. · Model engine fuel is also highly flammable. [. . . ] Synthetic oils are permissible but are less tolerant of a "lean run" than castor-oil. If, therefore, a synthetic lubricant is used in the fuel, readjust the needle-valve to a slightly richer setting, as a safety measure, in case the fuel/air mixture becomes too lean through maneuvers in flight. If a higher nitro fuel is used, the engine should be checked out to make sure that it is sufficiently run-in to operate on that particular fuel without overheating. Glow plug · · 2 Installing the propeller Washer · When to replace the glowplug Apart from when actually burned out, a plug may need to be replaced because it no longer delivers its best performance, such as when: Filament surface has roughened and turned white. Foreign matter has adhered to filament or plug body has corroded. Starting qualities deteriorate. · · · · · STARTING THE ENGINE Preparations 14 First, install the propeller on the engine by tightening the prop nut or spinner-nut lightly, and make sure of the position where compression is felt, turning the propeller counter-clockwise slowly. For accurately centering the starter's rubber drive insert, install an O. S. Wrench Alternatively, a spinner assembly, enclosing the propeller boss, may be used, but make sure that it isof sturdy construction and that the spinner shell does not loosen when the starter is used. Warning: When using a spinner assembly, make sure that the notches in the spinner shell are large enough to clear the propeller blades and so do not cut into and weaken the blade roots. Tighten the spinner nut firmly so that compression is first felt around this position (i. e. with blades horizontal) when turning the propeller in the direction of arrow. 4 Filling the fuel tank Do not allow fuel to overflow into silencer when refuelling, otherwise engine may become flooded and difficult to start. 3 Checking for gas leakage Check gas leakage by turning the propeller up to this position after compression is felt. Disconnect fuel line from the fuel inlet, and connect it to the tubing from the fuel pump. Be sure to observe the simple running-in procedures described on Page 22. If the engine stops when battery leads are disconnected, close the needle-valve a little (approx. 30°) further, and restart the engine. 20 18 Needle-valve adjustment(Summary) 6 Practical best(optimum) needle-valve setting Clear, high-pitched two-stroke exhaust note 5 7 Maximum rpm setting("Lean"). 20~30° 1 "Rich" needle-valve setting when starting the engine. d vol ec ut re io n s as st e. to art t de On starting from cold, with the needle-valve set at the rich starting position: a good deal of white smoke is emitted, accompanied by a relatively low-pitched "four-stroke" exhaust note. As needle-valve is closed and rpm increases an intermittent high-pitched two-stroke note will be superimposed on the low-pitched "four-stroke" note. Exhaust smoke will be less dense and grey in color. Further needle-valve closure: exhaust note is now a steady high-pitched sound, rising higher in pitch as needle-valve is closed and rpm increases. (However, make sure that engine is fully run in. ) Finally: maximum rpm is reached and will fall off (or engine will stop) if needle -valve is closed any further. Now, re-open needle-valve 20-30° This will produce the practical best (i. e. optimum) rpm setting (lower than maximum rpm). A light grey exhaust emission may be observed. [. . . ] Check that there is not something wrong with fuel tubing (kinked or split). Check that carburettor is not clogged with dirt. 3 5 Fuel not reaching the engine. 3 2 55 5 Mixture too rich. . Mismatch of glow plug and fuel. 27 CARE AND MAINTENANCE To ensure that you obtain long life and peak performance from your engine, observe the following. Avoid running the engine under dusty conditions. [. . . ]