Vire 7 - Operator's Manual Table of Contents Technical Data Engine Dimensions and clearances Mounting the Engine in the Boat Engine bed requirements Installation of the engine and propellor shaft Exhaust and cooling systems Additional installation notes Operation and Running Preparation of a new or stored engine Fuel and lubricants Starting Starting a warm engine Starting a very hot engine Engine Operation Engine speed and gearbox control Running-in period Stopping the engine Construction of the Engine General data Engine Cooling Carburettor Magneto Starter generator Reversing gear Maintenance Regular servicing Lubrication of the reversing gear Checking the spark plug Dampness in the magneto Cleaning the carburettor strainer Cleaning the carburettor Cleaning the air filter Adjustments Adjusting the carburettor Adjustment of the magneto breaker points gap Timing adjustment Dismantling and Reassembly Instructions Dismantling the engine Reassembling the engine Dismantling the reversing gearbox Reassembling the reversing gearbox Storage of the Engine Troubleshooting - List of Failures and Their Causes Technical Data - Engine Number of cylinders 1 Type 2-stroke / 2-cycle Bore 69.85 mm Stroke 70.00 mm Piston displacement 268 cc (16.35 cubic inches) Compression ratio 6.5:1 Power @ RPM 7 HP (5.1 kW) @ 3200 RPM Cooling Sea water cooling via an impellor type water pump driven directly from the gearbox Fuel pump A diaphragm pump incorporated in the carburettor, driven by pressure fluctuations in the crankcase Carburettor Tillotson HL Fuel Regular Petrol (Gasoline) (95 octane) The recommended mixture is: - 20 parts petrol to 1 part oil for the first 10 hours running 33 parts petrol to 1 part oil afterwards Lubrication oil: Engine 2-stroke (2-cycle) Super Outboard Oil (BIA Type TC-W) (mixed in fuel) Lubrication oil: Reversing gear (Gearbox) SAE 140 (ambient temperature above 10°C) SAE 90 (ambient temperature below 10°C) Webmaster's Note: The original Operator's Manual variously recommends 0.7 or 0.85 litres. Experience suggests that too much is better than too little. Fuel consumption 2.5 to 3 litres per hour, depending on RPM Spark plug - Normal circumstances, mild climate Bosch W95 T1 Champion UJ12 Champion RJ12C AC M47 Autolite A11X KLG FS30 or equivalent In exceptional conditions choose a hotter plug (light running, cold conditions) or a colder plug (heavy running, warm conditions) Spark plug gap 0.5 mm (0.020 inches) Flywheel magneto Bosch. Lighting power 6 volts / 16 watt (AC) Breaker points gap 0.45 mm (0.016 inches) Ignition timing 30° (5.8 mm before top dead centre) Starter generator Bosch 12 volt 90 watt Reversing gear Reduction ratio 2:1 Technical Data - Dimensions and Clearances Piston / cylinder 0.06 - 0.09 mm Piston ring gap 0.15 - 0.35 mm Side clearace of upper piston ring 0.060 - 0.085 mm Gudgeon pin to piston clearance 0.002 - 0.007 mm Gudgeon pin to connecting rod clearance 0.006 - 0.028 mm Side-play of connecting rod on crankshaft 0.20 - 0.30 mm End-play of screw shaft 0.1 mm Standard Equipment and Tools - See Spare Parts List. Mounting the Engine in the Boat To ensure reliable operation the engine must be mounted with great care. The fore and aft angle of inclination is recommended at 5°. The maximum of 10° must not be exceeded. The illustrations (not available in this .txt file) show the most important dimensions that need special attention during the mounting (all dimensions in mm). Engine Bed Requirements The engine bed should be sturdy and of solid construction. It is advisable to make the fore and aft bearers as long as possible, so that thrust will be transmitted through frames or ribs. The bed must also be firmly fixed to the transverse members. It is advisable to arrange the height of the engine bed so that shims or thin packing pieces can be inserted under the engine bearers. It will then be possible to obtain accurate alignment by removing or increasing the number of shims. Alignment should be checked at the beginning of and at least once during each season, as it is common for some craft to undergo slight changes in shape according to weather and drying out due to laying up conditions. Installation of the Engine and Propellor Shaft It is most important that the engine shaft and propellor shaft are in accurate alignment. The propellor shaft does not need any extra thrust bearing, as the rear bearing of the engine is capable of receiving the thrust. The propellor shaft system and the engine should first be assembled approximately in line. The exact centralisation and lining up is carried out by moving the engine little by little, after the propellor shaft system has been finally installed. When checking the final alignment of the engine, first tighten the fixing bolts of the engine, then remove the screws and the flexible disc of the coupling. The position of the engine is correct when the coupling flanges are centralised and completely parallel in all directions. The parallellism of the flanges can be confirmed by means of a feeler guage. If the distance between the flanges varies in any direction, the engine has to be moved sufficiently to correct any misalignment. When correct alignment is achieved, reconnect the coupling. Remove the spark plug and turn the shaft by hand. If the shaft rotates freely and evenly the engine/propellor shaft alignment is correct. When using a stern tube provided with a rubber-sleeve-mounted front bearing, the front end of the propellor shaft has to be centralised carefully to the stern tube before final checking is made. The centralisation is best achieved by disconnecting the sleeve, sliding the bearing assembly forward and locating the shaft in the tube with small wedges. Exhaust and Cooling Systems Despite the presence of cooling water, exhaust gases leaving the exhaust gas collector are still quite hot. The temperature of exhaust gases depends on the load and it can be as high as 300°C. If a hot exhaust is acceptable it can be left dry and the cooling water can be led from the cylinder directly to a discharge-overboard fitting. However, a hot exhaust pipe is generally to be avoided because of thermal radiation and the risk of fire. The preferred system is to raise the exhaust pipe immediately after the exhaust gas collector to a height sufficient to prevent sea water getting through the exhaust pipe to the engine. If there is no need to use a water jacket on the rising part of the exhaust pipe, cooling water is led directly into the exhaust pipe. In such a case the rising part of the exhaust pipe is hot and it has to be isolated and insulated from its surroundings. However, because the temperaure of the cooled part of the exhaust pipe does not exceed 100°C, that part of the pipe can be made out of suitable petrol-resistant plastic or rubber materials. In some cases it is not possible to get the bend of the exhaust pipe high enough immediately behind the engine. In such cases, a water jacket can be fitted immediately behind the engine, with a high bend further aft. If neither bend is high enough, but cooling of the exhaust is still needed, it can be arranged by leading a small amount of the cooling water through a regulator cock into the exhaust pipe. In this system, the main part of the cooling water is led from the cylinder directly through a hull fitting, as it is in a "hot exhaust" system. When using this system, the regulator cock must be opened immediately after starting the engine and closed before stopping the engine, if the engine is below or on the waterline. The exhaust pipe must always be installed so that any water coming past the exhaust pipe or condensing from exhaust gas in the exhaust pipe cannot flow into the engine. Additional Installation Notes When installing fuel pipes, absolute cleanliness must be observed. The fuel pipe can be made of suitable ¼" inside diameter pastic hose. If the engine is fitted in a confined space, e.g. in a sailing boat, special care must be taken to provide adequate ventilation in order to avoid fire risk. The starter battery must be firmly installed, easily accessible and adequately ventilated. Electrical components and cables must be mounted in such a way that vibration and dampness cannot cause any breakdowns. See wiring diagrams for the 12 Volt DC Starter Generator Electric System and the 6 Volt AC Lighting System. Operation and Running Preparation of a New or Stored Engine After storage, before the engine is put into service, the conserving oil must be drained from the crankase. This is simplified by pouring a cupful of 2-stroke fuel into the crankcase and then swinging the engine several times to and fro. The mixture is then drained out through the draining screw hole at the bottom of the crankcase. The preserving oil in the cylinder is removed in a similar manner, by pouring a spoonful of fuel through the spark plug hole, when the piston is #in the halfway position. The engine should then be rotated rapidly by the starter cord, the mixture blowing out through the spark plug opening. Fuel and Lubricants Any regular grade of petrol (gasoline) may be used. It is not necessary to use high octane or super grade fuel. The petrol should always be mixed with suitable oil, in the ratio of 1 part of oil to 33 parts petrol (1 part to 20 for the first 10 running hours). When filling the tank with fuel, use a fine mesh or chamois leather filter. The gearbox should be filled to the level between the end and the mark of the dip stick. Use gear oil SAE 140 for the initial 50 hours, thereafter use SAE 90 gear oil (Webmaster's Note: Some owners prefer always to use SAE 140). The capacity is 0.85 litres* (1.5 Imperial pints or 1.75 US pints). *Webmaster's Note: The original Operator's Manual suggests 1.5 Imperial pints (1.75 US pints - equivalent to 0.85 litres) under this heading, but then suggests 0.7 litres elsewhere in the Manual. Some later versions of the Manual advise the necessity of compensating for the tilt of the engine when filling the gearbox. Personal experience suggests that too much is better than too little (See "Stuck in Gear"). The grease cup on the inboard sterntube bearing should be filled with good quality water pump grease. Starting (See Maintenance) Check that adequate fuel is available in the fuel tank. Make sure that the gear lever is in the neutral position. Open the fuel cock (if fitted). If using a portable fuel tank, pump fuel with the hand pump until resistance is felt. Open the cooling water sea cock. If the engine is cold, close the choke (the choke lever on the carburettor should be in the upright position). Open the throttle about one third. If a Stop / Run switch is fitted, switch it to run. For engines with electric start, turn the starting key to crank the engine. For manual starting Wind the starter cord onto the starter pulley. Turn the engine slowly until compression is felt, then continue turning the engine to a position just over compression. Start the engine by pulling strongly and evenly on the starter cord. When the engine has started, turn the choke off slowly and use the throttle to regulate the speed accordingly. If a supply of water is led into the exhaust manifold through a regulator stop-cock, this should now be opened. Move the gear lever into the required driving direction. The speed of the boat is now adjusted by means of the throttle lever. Starting a Warm Engine Starting is generally the same as for a cold engine, except that the choke should be left in the run position (see above). No choke is used, because the mixture will be too rich and the engine will not start. If the engine has been 'flooded' or 'over-primed' the engine will not start. Proceed as follows: - Check that the choke is off, i.e. in the run position. Close the high-speed mixture screw (Webmaster's Note: If you note the number of turns by which you close the screw, it will make it easier to re-set the screw later). Open the throttle completely. Rotate the engine vigorously, several times if necessary, until it starts. As soon as the engine starts, re-set the needle valve to the best position and adjust the speed of the engine by means of the throttle. A very hot engine may refuse to start, even if not 'flooded'. In this case: - Check that the choke is off, i.e. in the run position. Open the throttle completely. Turn the fuel off. Give the engine several vigorous false starts. When the engine starts, adjust the speed of the engine by means of the throttle, then turn the fuel on. Remember: NO CHOKE when engine is hot Engine Operation Engine Speed and Gearbox Control Open the throttle lever to a 'fast idle' speed. Move the gear lever in the required direction (movement is 'instinctive'). WARNING ! The taper drive cone faces in the gear box can sieze and become seriously damaged if either forward or astern gear is selected with the engine running too fast. Set the engine speed just high enough to avoid stalling of the engine when the gear is engaged. The speed of the boat is adjusted by means of the throttle lever. The carburettor idling set screw should be positioned so that a hot engine will not cut out when the throttle is closed with the engine in gear. Running-in Period Careful use during the first 10 hours will increase the life of the engine. For the first five hours do not use more than half throttle, after which the maximum throttle opening can be increased gradually until at 10 hours it is safe to use full throttle. The engine will not develop full power for about 50 hours, by which time all the bearing surfaces will have become properly bedded in. For the first 10 hours it is advisable to use a slightly higher oil content in the fuel, i.e. 1:20. After the 10 hours running-in period, change to the normal 1:33 oil:petrol ratio. So-called Super Outboard Oils (BIA Type TC-W) are recommended. When running, check the flow of cooling water overboard (and through the exhaust, if applicable). During a long run, give an occasional turn to the grease cup of the stern tube bearing. Stopping the Engine If cooling of the exhaust pipe is arranged by "bleeding" some of the cooling water from the cylinder, close the regulator cock. Close the throttle to the idling speed position. Place the gear lever into the neutral position. Operate the ignition stop switch. Close the fuel cock. Close the sea cock at the cooling water inlet. NOTE: If the boat is to lie idle for some time, it is advisable to rotate the engine by means of the flywheel until compression is felt. When the piston is in this position it closes the ports in the cylinder wall, thus preventing humidity from entering the engine. Construction of the Engine General Data The Vire 7 engine is designed and built for marine use. The engine is supplied with a reversing gearbox and with its hand lever it is possible to select forward, neutral and reverse positions. The reduction ratio is 2:1. When moving forward the propellor rotates in the opposite direction to the engine. A flywheel magneto supplies current for ignition and a 6 volt 16 watt AC current for lighting, if required. The engine is supplied with a 12 volt starter generator; the power output of which, as a generator, is 90 watts. The carburettor is of membrane type, which guarantees the feeding of fuel irrespective of engine angle when the boat is under way. A vane type pump provides cooling water circulation. There is no thermostat in the cooling water system. Engine The engine is a single-cylinder, water cooled 2-stroke (2-cycle). The cylinder and cylinder head are cast in one piece. In order to achieve even running of the engine, an exhaust gas collector with a water jacket is fitted. This collector is beneficial in a 2-stroke engine, where the length, diameter and shape of the actual exhaust pipe and silencer can vary from boat to boat. In order to reduce weight, the collector has been made of light alloy. Because of this, the collector is water-cooled. This also reduces thermal radiation to the engine space and cools the exhaust. Cooling An impellor type water pump is fitted to the rear of the gearbox. It is driven through the gearbox by an extension of the idler gear shaft. The sea water suction line is connected directly to this pump, which pumps water through the exhaust collector water jacket and thence into the cylinder block. Because of this system, the cooling water thereby maintains the engine water temperature at an acceptable level under all running conditions. Webmaster's Note: It is important to pay attention to the seals between the water pump and the gearbox. If these fail, water will get into the gearbox, with potentially damaging results. Hot water from the pump can either be: - discharged directly overboard, or injected into the exhaust system at a point above the water line and used to cool the exhaust system, thus enabling rubber petrol-proof exhaust hose to be used for this water cooled section. (See Mounting the Engine in the Boat - Exhaust pipe, cooling water piping). Threaded plugs are fitted to the cylinder and the exhaust gas collector for the purpose of draining the system. Carburettor A diaphragm pump operated by pressure fluctuations in the crankcase is incorporated in the carburettor. The advantage of this type of carburettor is that it will function under all angles of heel. Fuel is drawn through a strainer into the pump chamber and is then transferred to the carburettor chamber where it is metered and controlled by a needle valve and the idling and main jets. A choke is fitted in the carburettor venturi to assist cold starting. Magneto Ignition is supplied by a flywheel magneto, which also incoporates a 6 volt AC lighting supply, if required. (See AC Lighting Wiring Diagram). The total power absorbed must not exceed 16 watts at 6 volts. Starter Generator The starter generator is driven from the crankshaft by a V-belt. When starting the engine it acts as a starter motor, drawing current from the 12 volt battery. The recommended capacity of the battery is 30-38 Ah (Maximum 45 Ah). When the engine is running the unit operates as a generator and produces current for battery charging and lighting if connected. (See Starter Generator Circuit Diagram) The cross section of the cables indicated by the thinner lines should be 2.5 sq.mm (0.0039 sq.in). The cross section of the cables indicated by the thicker lines is 16 sq.mm (0.025 sq.in). The electrical system comprises the following parts: - B - Battery G - Starter generator R - Voltage regulator and starting relay P - Instrument panel C - Charging lamp K - Key-operated starting switch F - Fuse box S - Switch L - Load (lights and electronic equipment) Reversing Gear The reversing gearbox is coupled directly to the rear of the engine. The propellor thrust is taken up within the gearbox. Forward and reverse action is provided by two cone clutches on a splined shaft. Maintenance Regular Periodic Service Beginning of the Season Remove excess protective oil from cylinder and crankcase Remove external protective greasing Clean carburettor and fuel pump Clean spark plug and check gap Check magneto contact breaker points gap and lubricate felt oiling pad Fill reversing gearbox with new oil Fill grease cup of the stern tube bearing with HMP grease Check condition and tightness of starter generator V-belt Check all electrical connections Check condition of battery Checks Before Normal Starting Fuel tank full (Do not use last season's fuel) Tightness of starter generator V-belt (occasionally) Check fuel and cooling system for leaks Lubricate stern tube bearing Every 50 Hours Running Clean spark plug and check gap Clean carburettor strainer In a new engine - change oil in reversing gearbox Check electrolyte level in battery Every 100 Hours Running In addition to the above mentioned servicing, change the oil in the reversing gearbox Every 300 Hours Running In addition to the above mentioned servicing, check the magneto breaker points gap and adjust it if necessary Clean carburettor Recommended Lubricants Stern tube bearing (Grease cup) - HMP grease Reversing gearbox (ambient temperature above 10 centigrade) - SAE 140 (0.85 litres*) Reversing gearbox (ambient temperature below 10 centigrade) - SAE 90 (0.85 litres*) Lubrication of Reversing Gear The reversing gearbox is filled with oil to the point where the tip of the dipstick just enters the oil when the dipstick is screwed down and the engine is in its normal position in the boat. The mark on the dipstick shows the absolute upper limit for the oil level. The amount of oil is 0.85 litres*. *Webmaster's Note: The original Operator's Manual suggests 0.7 litres under this heading, but then suggests 1.5 Imperial pints (1.75 US pints - equivalent to 0.85 litres) elsewhere in the Manual. Some later versions of the Manual advise the necessity of compensating for the tilt of the engine when filling the gearbox. Personal experience suggests that too much is better than too little (See "Stuck in Gear"). Checking the Spark Plug When setting the spark plug gap, adjust the earth connection electrode, not the middle electrode. The gap should be set to 0.50 mm. About 99 per cent of running and starting difficulties in 2-stroke engines originate in the spark plug. If your engine has been running well and for some unexplained reason starts developing starting or running faults, always check the plug first. Better still, fit a known serviceable spark plug and have the other cleaned and re-gapped. Always keep with you at least one serviceable plug wrapped in a plastic bag. Do not leave it in the boat. Take it from your dry, warm house to the boat each trip. If you know that there is fuel and compression - that the engine is not 'flooded' or over/under choked - and yet it still will nor start after four or five attempts - save yourself a lot of wasted effort by checking the plug. In nine out of ten cases cleaning the plug will effect a cure and the other one out of ten cases will almost certainly be corrected by a change of plug. Laying the plug on the cylinder head with the high-tension (HT) lead connected and engine rotated will tell you if the plug is sparking, but you should for a good 'fat' blue spark. A plug that gives a thin or white spark may not spark at all when under compression in the cylinder. The best rule with spark plugs is 'When in doubt, have it out !' Dampness in Magneto If there is any reason to suspect that there is dampness in the magneto, remove the rope starting pulley and spray a dampness remover (e.g. CRC 5-56 or WD-40) through the flywheel holes into the magneto. If the engine will not start after this procedure, remove the flywheel and armature and dry it properly. The above-mentioned dampness removers can also be used on other electrical devices in the engine. Cleaning the Carburettor Strainer In order to clean the carburettor strainer, remove the screw and strainer cover from the bottom of the carburettor, taking care not to damage the gasket. Wash the strainer with petrol, and dry it. When putting the strainer back, check the gasket and fit the cover with care to avoid leaks. Cleaning the Carburettor When the engine is laid up for a long period, the lubrication oil can separate from the fuel and clog the carburettor. In such a case, remove the screw of the idling speed nozzle (idle mixture screw) and the screw of the main nozzle (high speed mixture screw), being careful not to lose any springs, washers or sealing rings. Put a can under the carburettor and let the fuel flow for some time through the screw holes. If the fuel tank lies below the carburettor, a flow can be created by removing the spark plug and rotating the engine by hand. After this, replace the nozzle screws and adjust the carburettor. If you have to strip the carburettor, ensure cleanliness and handle membranes and their sealing surfaces with care. An air leak on a sealing surface, valve or connection can cause a malfunction in the carburettor. In order to clean internal channels, use petrol and compressed air. Do not, under any circumstances, use steel tools, needles or similar articles to clear internal blockages. Cleaning the Air Filter The air filter is of the dry type. Wash the filter at the end of the season and/or when required. Adjustments Adjusting the Carburettor Idling Speed (Idling Jet / Idling Mixture & Throttle Stop Screw / Idling Speed Screw) Clean the spark plug and check the spark plug gap. Unscrew the idle mixture screw one a quarter turns. (A screwdriver is needed for this adjustment). Start the engine and run until warm. With the gear lever in neutral, close the throttle and set the speed to 1200 r.p.m. (At this speed, the engine will tend to 'four-stroke'). Put the gear lever into the 'ahead' position. The engine speed should not fall below 1000 r.p.m. If the engine speed falls below 1000 r.p.m. in 'ahead' at low throttle, adjust the idle speed screw until the engine is running at 1000 r.p.m. Full Power (Main Jet / High Speed Mixture Screw) Preliminary Setting of Main Jet - Open the high speed mixture screw one and a quarter turns. (This is done by hand, without the need for a screwdriver.) Final Setting of Main Jet - This must be carried out when the boat is underway. Depending on the type and size of boat, the high speed mixture screw may need to be adjusted either way to obtain maximum speed. Adjustment of the Magneto Breaker Points Gap The magneto contact breaker points gap in a new engine is adjusted at the Factory to its proper value. After 300 running hours it may be necessary to check the gap and possibly readjust it. The following procedure should be adopted: Remove the starter pulley. Rotate the crankshaft until the breaker point gap is at maximum. The breaker point gap should be set to 0.45 mm (0.016 inches) by means of a feeler gauge. If necessary, adjust the gap by loosening screw #1 and turning point #2 from notch A. Retighten screw #1. Timing Adjustment The timing is adjusted at the factory to its proper value to give the greatest efficiency and starting characteristics. If the magneto statorplate has been removed it must be fitted so that the fixing screws pass centrally through the oval shaped slots. This will ensure the correct timing, provided that the magneto contact breaker points gap is correct. If rechecking or adjustment of the timing is needed, the following procedure should be adopted: Check the magneto breaker points gap and adjust it if necessary. Turn the flywheel clockwise (direction of normal rotation) until the notch on the V-belt pulley indicates the fixing level of the bracket on the left side of the engine (when viewed from the front). The breaker points should just open at this position, which is 30 degrees before top dead centre (BTDC). This corresponds to the position of the piston in the cylinder being 5.8 mm (0.23 inches) BTDC, which can be measured with a depth gauge type timing tool through the spark plug hole. The only accurate way to check the opening of the points is with a buzzer type continuity tester. If the timing is correct a sound change is noted at this position, 30 degrees BTDC. If the timing is incorrect, loosen the fixing screws of the stator plate - shift the plates clockwise if the points are opening too early - shift the plates anti-clockwise (counter clockwise) if the points are opening too late - repeat until the timing is correct. Retighten the fixing screws on the stator plate. Recheck the magneto breaker points gap and readjust it if necessary. Dismantling and Reassembly Instructions Dismantling the Engine Flywheel Removal Remove the V belt cover and the V belt Remove the fixing screws of the starting pulley and remove the pulley Using the special puller supplied, fit it to the flywheel with screws and tighten the puller centre screw against the end of the crankshaft Tap the head of the puller screw lightly with a hammer to loosen it. The flywheel should then be easily removed from the cone. Webmaster's Note: Take care not to lose the Woodruff key when removing the flywheel. To Open the Crankcase Drain the oil from the reversing gearbox Remove the exhaust gas collector Remove the starter generator and the V belt cover Remove the flywheel as described above Remove the fixing screws of the reversing gearbox and separate it from the crankcase by use of a hide hammer. Do NOT force any hard tool between the flanges Remove the cylinder Remove the fixing screws between the two halves of the crankcase and separate the two halves Remove the crankshaft from the crankcase Engine Assembly Note: If the crankshaft is damaged, return it to the Manufacturer or to a Workshop recommended by the Manufacturer, to be repaired. Oil lightly all the moving parts and shaft seals, paying particular attention to cleanliness. The assembly is carried out in the following sequence: Assemble the bearings on the crankshaft and, using a suitable sleeve, tap against the inner ring of the bearing until it is in its correct position Assemble the shaft seals, taking care not to damage them Fit the crankshaft to the rear part of the crankcase, coat the sealing surfaces evenly with sealing compound and assemble the front part of the crankcase on the crankshaft, ensuring that the cylinder head joint surface is level Tighten the fixing screws Check the assembly of all parts installed so far by rotating the crankshaft Fit the piston assembly, ensuring that the piston ring grooves face the front (flywheel end) of the engine Assemble the cylinder and its gasket Assemble the magneto armature, flywheel and starting pulley Refit the reversing gearbox Assemble the starter generator, V belt, V belt cover, carburettor and exhaust gas collector Mounting the Flywheel Assemble the flywheel on the crankshaft, ensuring that the Woodruff key enters the keyway provided Replace the nut on the flywheel and tighten it with a torque spanner (torque wrench) to 10 kpm. If a torque spanner is not available, adopt the following procedure: tighten the nut with a suitable socket wrench or box spanner as much as possible while holding the flywheel with the other hand tighten the nut 1/6 (one sixth) of a turn by tapping the end of the spanner with a hammer If the fixing holes of the starting pulley do not line up with the corresponding holes in the flywheel, the nut must be tightened still further until the holes line up. The torque must never be reduced in order to effect the lining-up of the holes. Dismantling the Reversing Gearbox Drain the oil from the reversing gearbox Separate the reversing gearbox from the engine as described in "Dismantling the Engine" Remove the water pump from the rear of the reversing gearbox by removing the housing fixing screws, then removing the case, impellor and gasket Using the impellor puller provided, remove the coupling flange Remove the shafts from the casing by pulling them forward. Use a hide hammer on the rear part of the shaft if difficulty is experienced Remove the gear lever (coupling rod) from the coupling crank by removing the elastic taper pin in the end of the shaft. When removing the gear lever, take care not to lose the spring and locating pin Remove the coupling crank from inside the gearbox The gear wheel of the reversing gear and its bearing can be removed by removing the locking ring from the shaft end Remove the bearings, taking care not to damage the cone surfaces and the splined shaft Reassembling and Refitting the Reversing Gearbox Assemble the shaft seals Assemble the shaft bearings, using a sleeve of suitable diameter to apply pressure to the inner ring of the bearings Complete the main shaft assembly (cones, gear wheels, bearings and retaining rings) Assemble the main shaft bearings, using shims where necessary Refit the coupling crank and and refit the gear lever (coupling rod) Refit the shafts Refit the water pump assembly Assemble the sleeve, key and coupling flange on the external end of the main shaft Refit the reversing gearbox to the engine Check the endplay of the propellor shaft, which should be approximately 0.1 mm. If necessary, adjust with suitable adjusting shims Fill the reversing gearbox with gear oil Storage of the Engine Ideally, when laying up the engine for the winter or if it is not to be used for a considerable period, the engine should be removed from the boat and stored in a cool dry location, suitably covered to protect it from dust and dirt. If this is not possible, the following procedure shuld be adopted: - Remove the air filter, start the engine, and spray protective oil (Part No. 50 173) into the inlet manifold Open the plug on the cylinder block (Fig. 11 Ref. No. 11) and the plug in the sound absorber (Fig. 16 Ref. No. 8). Ensure that all the water drains out. If protective oil in a spray bottle is not available, proceed to the following four stages: Remove the carburettor, spark plug and V belt With the piston at Top Dead Centre, pour about 140 mls (¼ Imperial Pint) of oil through the suction point into the crankcase Turn the piston down to Bottom Dead Centre and tilt the engine so that the oil can flow onto the bearings Turn the piston again to its Top Dead Centre position and pour about a spoonful of motor oil through the spark plug hole into the cylinder Rotate the crankshaft two or three turns, leaving it in mid-stroke position, so that the cylinder ports are covered Replace the spark plug and grease all exposed metal parts To protect electrical components, spray them with a suitable water-repellant spray Clean the battery, check the electrolyte level in it, and charge it Troubleshooting Start by checking the basics - make sure that the Stop/Run Switch (if fitted) is switched to Run and make sure that there is fuel in the tank and that it is reaching the engine. After that, most cases of failure to start are due to problems with the spark plug, so check the spark plug before you do anything else. If that doesn't work, determine which of the following descriptions most closely matches the problem, then check against the "X"s in the table below for a list of possible causes. Problems are tabulated under five headings: Engine does not start or it stops during running Engine runs irregularly Engine output is too low Engine "knocking" Flywheel striking back 1 2 3 4 5 Possible cause X O O O O Fuel tank empty X O O O O Too much choke X O O O O Water in fuel X X O O O Carburettor main nozzle clogged X X O O O Carburettor strainer clogged X X O O O Fuel tank vent hole blocked X X X O O Unsuitable fuel X X O O O Air leak in carburettor X X X O O Spark plug electrodes dirty or burned X X O O O Spark plug gap too big X X O O O Water drops on spark plug electrodes X X O O O Defective insulation X X O O O No contact between plug terminal and cable X X O O O Magneto contact breaker gap short-circuited or insulation dirty X X O O O Magneto contact breaker gap too big or too small X X O O O Ignition cable (magneto end) or inner wires loose X X O O O Magneto wet X X O O O Other reasons X O X O O Piston rings stuck O O X O O Ignition advance too small O O O X O Carbon on pistons or at cylinder end O O O X X Ignition advance too great