It is of vital importance, before attempting to operate your engine, to read the general 'safety instructions and warnings' section on pages 2-3 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...
Contents 2 ~ 3 4 5 6 7 8 9 10 11 12 ~ 13 14 15 16 17 18 19 safety instructions and warnings about your o.S. Engine fitting the glowplug, installation of the carburettor basic engine parts piping, installation, linkages fuel and glowplug flexible drive shaft, propeller, before starting the engine adj...
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 fut...
Notes this engine was designed for model boats. Do not attempt to use it for any other purpose. Mount the engine in your model securely, following the manufacturers' recommendations, using appropriate screws and locknuts. Fit an effective silencer(muffler). Frequent close exposure to a noisy exhaust...
Fitting the glowplug the o.S. Max-21xm is a high-performance water-cooled outboard marine engine for small and medium-size radio-controlled outboard boats. It is of sturdy construction and designed for easy maintenance. It is not necessary to readjust the linkage when the installation angle to the h...
Basic engine parts carburettor(os type 20j) needle-valve water-cooled cylinder head e-2050 silencer water inlet tube exhaust outlets cooling water pickup carbon-reinforced propeller skeg outboard unit lower housing cavitation plate oil transfer tube transom mounting plate steering arm throttle linka...
Piping connect the water inlet tube (l=170mm) and oil transfer pipe (l=65mm) securely as shown on page 5. In the event of either tube becoming damaged, it should be replaced with best quality 5.5mm od ✕ 2.5mm id silicone tubing. Installation the face of the mounting plate is precision machined flat....
Fuel use only top quality commercial model two-stroke engine fuel. For consistent performance and long engine life, it is essential to use fuel containing at least 18%(volumetric ratio)best- quality lubricant. This engine is designed to run on both low and high nitromethane content fuels, i.E. From ...
Propeller the max-21xm's special carbon-fibre propeller has a diameter of 42mm and a p/d ratio of 1.2. If any other propeller is substituted, make sure that it is properly balanced. Flexible drive shaft if, due to accidental damage or wear, the flexible drive shaft (see p.16) should require replacem...
Before starting the engine for the first run of the day, remove the glowplug and check the engine by rotating the flywheel by hand. It should rotate smoothly. Now turn the engine with an electric starter until fuel is drawn into the carburettor. At first, rotation may feel 'sticky' due to oily resid...
Starting set the needle-valve. Turn the needle clockwise slowly, without forcing, until it stops. Then, reopen the needle-valve 2-1/2turns counterclock- wise. Open the throttle very slightly: heat the glowplug by connecting the battery leads. Make sure that the direction of rotation of the electric ...
Running-in (''breaking-in'') for long life and high-performance, every engine needs to be properly 'run-in' or 'broken-in'. There are several running-in methods, but the following is suitable for use with the max- 21xm. It is vitally important to set the throttle at the correct starting position bef...
Adjustment open the throttle slightly from the idling position and start the engine, following the procedure described previously. Lower the boat into the water, gradually open the throttle and run the boat straight ahead for 20 to 30 metres at full throttle. Now return the model and close the needl...
Carburettor cleanliness proper functioning of the carburettor depends on its small fuel orifices remaining clear. The minute particles of foreign matter that are present in any fuel, can partially obstruct these orifices and upset mixture strength so that engine performance becomes erratic and unrel...
✽ o.S. 'super-filters' (large and small) are available, as op- tional extras,to deal with this problem. One of these filters, fit- ted to the outlet tube inside your refuelling container, will pre- vent the entry of foreign material into the fuel tank. Care and maintenance to ensure that you obtain ...
4 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 too...
Exploded view 1 1-1 2 3 4 5 6 7 8 9 10 11 11-1 12 13 14 15 16 17 18 19 20 21 22 23-a 23-c 23-b 23-d 23-e 23-f 23-g 23-h 23-i 23-j 23-k 23-l 23-m 24 25 23 23-c1 23-c2 c.M3x12 c.M2.6x18 c.M2.6x18 c.M2.6x10 n.M3x10 n.M3x12 c.M3x10 c.M2.6x8 f.M3x10 n.+m3x10 c.M4x12 n.+m4x8 c.M4x12 f.M3x8 13-1 13-2 13-3 ...
7 1802 100 2 7721 700 4 1614 000 2 3851 000 2 3981 700 7 1532 000 2 5382 000 2 3805 000 2 3817 000 2 3906 000 2 3803 010 2 3841 000 2 4025 923 2 3913 000 2 3875 000 2 3875 300 2 2681 953 2 3875 400 2 3930 000 2 3852 000 2 3852 100 2 2631 019 2 3814 010 no. 1 1-1 2 3 4 5 6 7 8 9 10 11 11-1 12 13 13-1...
2 4981 405 2 6381 501 2 5381 203 2 6781 309 2 4881 824 2 6781 506 2 5382 100 2 5381 220 no. 1 1-1 2 3 3-1 4 5 6 throttle lever assembly set-screw carburettor rotor mixture control valve '' o '' ring (2pcs.) rotor spring carburettor body rotor guide screw code no. Description fuel inlet needle valve ...
Displacement bore stroke practical r.P.M. Power output weight 3.46 c.C. ( 0.211 cu.In.) 16.6 mm ( 0.654 in.) 16.0 mm ( 0.630 in.) 3,000~25,000 r.P.M. 1.3 bhp / 25,000r.P.M. 670g ( 23.6 oz.) ■ ■ ■ ■ ■ ■ 48.5 37.5 46 45 25 149.5 219 46 34.5 86 183 87 64 48.5 46 specification three view drawing 19.
Memo 20
C copyright 2000 by o.S.Engines mfg. Co., ltd. All rights reserved. Printed in japan. Un eq ua lle d qu ality precision & perfo rma nc e est ablish ing the standards of ex cel len ce tel. (06) 6702-0225 fax. (06) 6704-2722 6-15 3-chome imagawa higashisumiyoshi-ku osaka 546-0003, japan 100101 url : h...
