FLAT-TWIN FOUR STROKE ENGINE Gemini SERIES OWNER'S INSTRUCTION MANUAL OSAKA-JAPAN
IMPORTANT: Before attempting to operate your engine, please read through these instructions and separate sheet enclosed so as to familiarize yourself with the controls and other features of the engine. Also, pay careful attention to the recommendations contained in the "Safety Instructions and Warnings" leaflet enclosed. Your "Gemini Series" engine is a scale-type horizontally-opposed twin-cylinder overhead-valve four-stroke-cycle engine.
Gemini SERIES Right (No.2) cylinder Safety propeller locknut assembly Left (No.1) cylinder Cylinder head Crankcase Rocker cover Exhaust pipe Push rod cover Carburettor (Photo shows FT-160) There are small differences in the appearance of the other Gemini engines. -2- Photo.
NAMES OF ENGINE PARTS Rear housing Intake pipe (left) Intake pipe (right) Breather nipple Fuel inlet Intake manifold Choke valve (Photo shows FT-160) There are small differences in the appearance of the other Gemini engines. -3- Photo.
INSTALLATION "Gemini Series" engines should be mounted with the carburettor below the crankcase, otherwise scale appearance may be spoiled, if the tank is located high, fuel will flow into the carburettor when the tank is full. Therefore, pinch the fuel line with a clip, when the engine is not running, to prevent flooding and loss of fuel. The needle-valve and throttle lever locations are interchangeable and the choke valve rod can be located right or left.
GLOWPLUG With a four-stroke engine, ignition of the fuel charge takes place at every fourth stroke of the piston instead of every two strokes. Because of this, conventional two-stroke glowplugs may not suit this engine in some cases. For general use, the special O.S. Type F glowplug is recommended. CHOKE VALVE "Gemini Series" engines are equipped with a spring-loaded choke valve. The choke valve operating lever can be located right or left by reversing the hexagon nut and cap screw.
CARBURETTOR The needle-valve and throttle lever locations are interchangeable by reversing the carburettor. This can be done as follows: Remove the carburettor carefully by unscrewing the two screws which secure both carburettor and choke valve. After reversing the carburettor, re-insert it into the intake manifold, taking care not to damage the 0-ring in the manifold. Carburettor and choke-valve fixing screws Fig.
PROPELLER Lockout spacer The choice of propeller depends on the size and weight of the model and on the type of flying envisaged. Determine the best size after practical experiment. Suggested propellers are shown in the separate instructions sheet. For safety, keep your face and other parts of the body well away from the propeller when starting the engine or when adjusting the needle-valve while the engine is running.
Installation procedure is as follows: 1) Ream the propeller centre hole to the separate instructions sheet. propeller is properly balanced. 2) Fit the propeller sleeve-nut and screw onto shaft and tighten firmly supplied. If the Safety Propeller Lockout Assembly of your engine is supplied with the Locknut Spacer, add the Spacer if the dimension "T" indicates you should do so, in the separate instructions sheet. 3) Finally, insert the Safety Propeller Locknut.
Regardless of the type of propeller fixing used, make a habit of always checking the tightness of the propeller before starting the engine. Remember that, especially with wooden propellers, there is a tendency for the material to shrink, or for it to be reduced by the serrated face of the drive hub. When removing the propeller from the engine between flying sessions, it is recommended to withdraw it complete with drive hub, instead of removing the six retaining screws.
Battery Leads As the battery leads are required to conduct a large current (approx. 6 amps), make sure that the wire used is heavy enough to prevent excessive voltage-drop at the plugs. Note: It is inadvisable to use a variable resistance or rheostat as, in the event of one plug lead becoming accidentally detached (or the plug element failing) excessive voltage will be applied to the other plug. The alternative is to use a separate battery and rheostat for each plug.
the needle-valve may cause the engine to stop, especially when it is new and insufficiently run-in. 9) To re-start the engine when it is warm, after a run, first try just flipping the prop with the throttle in the idling position after re-energising the glowplugs. If the engine does not restart, re-prime it by closing the choke valve while rotating the propeller twice with the throttle open.
RUNNING-IN ("Breaking-in") VALVE CLEARANCE ADJUSTMENT For long life and peak performance, please observe the following running-in procedure: Install the engine and fit the propeller that you propose to use for flying your model. For example, if you use the propeller indicated in the separate instructions sheet, start the engine and run it for about 10 seconds with the needlevalve set for 6,000/6,500 r.p.m., then open the needlevalve to reduce speed to approximately 4,000 r.p.m.
At the conclusion of a flying session, do not leave the engine "wet" with raw fuel by stopping it after rich-mixture running or prolonged idling. Instead, let it run for a few moments at full throttle with the correct needle-valve setting, to bring it up to normal running temperature, then cut off the fuel supply — preferably by removing the fuel line from the carburettor.
MEMO -14-
O.S.ENGINES MFG.CO.LTD 6-15 3-Chome Imagawa Higashisumiyoshi-ku Osaka 546-0003, Japan TEL. (06) 6702-0225 FAX. (06) 6704-2722 URL: http://www.os-engines.co.jp © Copyright 2000 by O.S.Engines Mfg. Co., Ltd. All rights reserved. Printed in Japan.
INSTRUCTIONS FOB O.S. FT-160 (GEMINI-160) TWIN-CYLINDER FOUR STROKE ENGINE IMPORTANT: Before attempting to operate your engine, please read through this instruction sheet, as well as the GEMINI SERIES Owner's Instruction Manual supplied, so as to familiarize yourself with the controls and other features of the engine. Also, pay careful attention to the recommendations contained in the "Safety Instructions and Warnings" leaflet also enclosed. The O.S.
1) Start the engine, with the throttle 1/3 open from the fully closed position, then open the throttle fully and gradually close the needle-valve until the engine is running at its maximum speed. CAUTION: possible idling speed, without stopping the engine, may be obtained. Do not close the needle-valve to too "lean" a setting as this will cause the engine to overheat and slow down. Set the needle-valve very slightly to the "rich" side of the peak r.p.m. setting.
