It is of vital importance, before attempting to operate your engine, to read the general 'safety instructions and warnings' section on pages 2-6 of this booklet and to strictly adhere to the advice contained therein. Also, please study the entire contents of this instruction manual, so as to familia...
2 remember that your engine is not a "toy", but a highly efficient internal- combustion 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. If at some fu...
4 notes this engine was designed for model aircraft. Do not attempt to use it for any other purpose. Mount the engine in your model securely, following the manufacturers' recommenda- tions, using appropriate screws and lock- nuts. Be sure to use the silencer (muffler) supplied with the engine. Frequ...
6 notes adjust the throttle linkage so that the engine stops when the throttle stick and trim lever on the transmitter are fully retarded. Alternatively, the engine may be stopped by cutting off the fuel supply. Never try to stop the engine physically. Take care that loose clothing (ties, shirt slee...
8 notes when applying an electric starter do not over-prime. This could cause a hydraulic lock and damage the engine on application of the electric starter. If over-primed, remove glowplug, close needle-valve and apply starter to pump out surplus fuel. Cover the head with a rag to prevent pumped out...
10 max -35ax is shown. Basic engine parts cylinder head carburetor type 21k crankshaft propeller nut propeller washer drive hub crankcase cover plate glowplug beam mount (type 21l for 25ax) 11 9x5-6, 9.5x5, 10x5 size(dxp) 10x6-7, 11x6, 12x6 25ax 35ax tools, accessories, etc. The following items are ...
12 fuel the 25ax and 35ax should be operated on a methanol based fuel containing not less than 18% (volumetric) castor oil, or a top quality synthetic lubricant (or a mixture of both), plus a small percentage (5-20%) of nitromethane for improved flexibility and power. (the carburetor is adjusted a l...
14 8mm tools hex screwdriver screwdriver necessary for engine installation. 1.5mm, 2.5mm necessary for mixture control valve adjustments. Phillips screwdriver no.2, etc. Long socket wrench with plug grip recommended for easy removal and replacement of the angled and recessed glowplug, the o.S.Long s...
16 how to fasten the mounting screws. Hardwood mounting beams radial motor mount (cast aluminum) tighten second nut firmlydown onto first nut. Tighten this nut first. Steel washer 3mm steel nuts 3mm steel screw spring washer or lock washer 12mm min. 12mm min. Hardwood such as cherry or maple. Spring...
18 installing the glowplug install washer on glowplug and insert carefully into cylinder-head, making sure that it is not cross-threaded before tightening firmly. Glow plug washer needle-valve extension the needle-valve supplied with this engine is designed to incorporate an extension so that, when ...
20 suggested fuel tank capacity is approx 160cc. This will allow 10-12 minute flights. Be sure to use a pressurized fuel system by connecting the muffler pressure nipple to the vent-pipe of the fuel tank. Fuel tank location make sure that the tank is well rinsed out with methanol or glow fuel before...
22 the needle valve when set to produce maximum power at full throttle, this establishes the basic fuel/air mixture strength. The correct mixture is then maintained by the carburetor's built-in automatic mixture control system to cover the engine's requirements at reduced throttle settings. The mixt...
24 ! Starting be sure to use an electric starter to start the engine. Fill the fuel tank with fuel. When filled, prevent the fuel from flowing into the carburetor with a commercially available fuel stopper, etc. Release the stopper before starting the engine. 1. 2. Starting procedure is as follows: ...
26 attention : do not choke the carburetor air intake when applying the starter. This could cause an excessive amount of fuel to be drawn into the cylinder which may initiate a hydraulic lock and damage the engine. If the engine does not start within 10 repeat applications of the starter, remove the...
28 during subsequent flights, the needle-valve can be gradually closed to give more power. However, if the engine shows signs of running too lean, the next flight should be set richer. After a total of ten flights, the engine should run continuously, on its optimum needle-valve setting, without loss...
30 idling adjustment char t start the engine. Make sure that the throttle is fully open. Adjust the needle-valve. Close the throttle gradually. Set the idle speed open the throttle fully. Does the engine regain full power? Continue running at high speed for 10 seconds. Close the throttle. Run at idl...
32 realignment of mixture control valve subsequent starting procedure once the optimum needle-valve setting has been established (see page 29, needle-valve adjustment diagram) the procedure for starting may be simplified as follows. Open the needle-valve one half-turn (180 degrees) from the optimum ...
34 1 2 3 symptom factor cause corrective action recharge the electric starter battery. Recharge lead-acid cell or replace dry battery. (note: an unused, or almost unused, dry battery may sometimes be of insufficient capacity if it is "old stock".) replace glowplug. Check that applied voltage is not ...
36 care and maintenance please pay attention to the matters described below to ensure that your engine serves you well in regard to performance, reliability and long life. As previously mentioned, it is vitally important to avoid operating the engine in conditions where dust, disturbed by the propel...
38 25ax engine exploded view type of screw c...Cap screw cap screw sets (10pcs ./sets ) code no . Si ze pcs . Used in an engine cylinder head retaining screw (4pcs.) cover plate retaining screw (4pcs.) 79871020 79871140 m2.6x7 m3x12 c.M3x12 c.M2.6x7 2 1 3 4 5 6 7 8 9 10 12 11 13 14 15 16 17 39 25ax ...
40 1 2 4 5 7 s.M3x3 3 6 3-1 3-2 7-1 7-2 8 8-1 n.+m3x6 9 n.+m3.5x5 10 21l carburetor exploded view type of screw n...Round head screw s...Set screw 41 21l carburetor parts list specifications are subject to alteration for improvement without notice. 22081408 22582200 29181620 46066319 22781800 225821...
42 c.M3x15 c.M2.6x7 2 1 3 4 5 6 7 8 9 10 12 11 13 14 15 16 17 35ax engine exploded view type of screw c...Cap screw cap screw sets (10pcs ./sets ) code no . Si ze pcs . Used in an engine cylinder head retaining screw (4pcs.) cover plate retaining screw (4pcs.) 79871020 79871150 m2.6x7 m3x15 43 35ax ...
44 1 2 4 5 7 s.M3x3 3 6 3-1 3-2 7-1 7-2 8 8-1 n.+m3x6 9 n.+m3.5x5 10 21k carburetor exploded view type of screw n...Round head screw s...Set screw 45 21k carburetor parts list description code no. No. Specifications are subject to alteration for improvement without notice. Throttle lever assembly ca...
46 o.S.Glow plug o.S. Genuine parts & accessories radial motor mount silencer extension adaptors width screw hole pitch (72403050) super filter (l) (71908410) (22625103) 12.5mm 35.0mm (23024008) 1/4"-28 (73101020) (73101000) 1/4"-28 (23024009) 1/4"-28(l) spinner nut long propeller nut set propeller ...
48 4.07 cc / 0.248 cu.In. 18.0 mm / 0.709 in. 16.0 mm / 0.630 in. 0.7 ps / 0.71 hp / 14,000 r.P.M. 2,500-15,000 r.P.M. 0.8 ps / 0.81 hp / 16,000 r.P.M. 2,500-17,000 r.P.M. 275 g / 9.70 oz. 83.0 g / 2.93 oz 15 19 19 38 33.6 96.2 80.5 18 30.6 45 25 26 76.8 22.5 53 24 99.5 30.5 59.2 unf1/4-28 35 displa...
50 memo c copyright 2009 by o.S.Engines mfg. Co., ltd. All rights reserved. Printed in japan. 60092180 061101 6-15 3-chome imagawa higashisumiyoshi-ku osaka 546-0003, japan url : http://www.Os-engines.Co.Jp.
