Flywheel removal is one of the most demanding and technically challenging procedures in the maintenance of an outboard motor, most often required to replace it. squirrelIncorrect performance of actions can lead to damage to the crankshaft, failure of thread or violation of the balancing of the unit, so the approach should be as careful as possible.
Before starting work, you need to fully strip off And so, to allow free access to the top of the engine, ignoring the technology of removables often ends up with the flywheel clinging to the cone, and removing it becomes a real torture.
During the preparation process, make sure you have all the necessary tools, including a dynamometer key and flywheeler Many beginners make the mistake of trying to knock a flywheel down with a hammer, which is strictly forbidden, as it is guaranteed to disrupt the landing geometry. Below we will discuss the steps of work in detail so that you can perform the repairs efficiently and safely for the unit.
Necessary tools and workplace preparation
Well, good training is half the success of any mechanical operation. To remove the flywheel, you'll need not only a standard set of carob and cape keys, but also a specialized tool that makes it impossible to work without. flywheelerIt should match the seat on your engine to avoid damaging the thread.
It is also critical to have a piston fixture or a special stop at hand that will prevent the crankshaft from turning when the nut is unscrewed. Trying to hold the flywheel with your hand or mounting through the starter teeth (on electric starter models) often leads to a break in the crown or damage to the fingers.
- 🛠️ Flywheel Removal (universal or specific to the brand of the motor)
- 🔧 Dynamometer key with a range of up to 100 Nm
- 🔨 Hammer (preferably with copper or polyurethane brisket)
- 🧴 Penetrating lubricant (WD-40 or analog) and brake cleaner
⚠️ Attention: Never use a chisel or screwdriver between the flywheel and the crankcase to loosen the piece, which will cause chips on aluminum and break the tightness of the crankcase.
The workplace should be clean, because when you remove the flywheel, you can access the omentation glands, and any dirt that gets inside will instantly disable the new seal, and it is recommended to blow the area around the crankshaft with compressed air and wipe the visible surfaces with rags soaked in the degreaser in advance.
Dismantling of external components and ignition system
The first step is to free up access to the flywheel fastener, which requires removing the top casing of the engine and removing all the plastic shields that cover the flywheel and the stator. Yamaha and Suzuki will also need to remove the control panel or sensors attached directly to the flywheel.
Special attention should be paid to wiring. Before pulling the flywheel, you need to carefully disconnect the connectors of the ignition coil (stator) and the throttle position sensor, if it is located in this area. Often the wires pass through special channels or holders that need to be released so as not to damage the insulation when removing the unit.
After removing external obstacles, the central nut of the flywheel attachment is unscrewed. It is important not to lose the washer and the nut itself, since they often have a specific design. Before unscrewing, it is recommended to treat the threaded joint with penetrating lubricant and withstand 10-15 minutes.
Wrap the base of the flywheel with a rag before unscrewing the nut so that random drops of old oil or rust do not fall on the ignition coil.
If the motor is equipped with an electric starter, make sure that the bendix does not interfere with access to the nut. In some cases, you need to remove the starter first. After successfully unscrewing the nut, do not rush to remove it completely - leave a few turns of thread so that the flywheel does not fall suddenly and damage the veneer.
Crankshaft fixation and nut unscrewing
The most important point of the preparatory stage is the reliable fixation of the crankshaft. The timing of tightening the flywheel nut is usually between 60 and 120 Nm, so you can not hold the shaft with your hands. Using "grandfather" methods, such as inserting a rope into a candle hole, can be effective, but requires caution so as not to damage the piston or rod.
The most professional approach is to use a special crankshaft stopper that is inserted into the process hole of the crankcase. For two-stroke motors, the method of blocking through the purge window is often used, but this requires high skill and understanding of the tactile sensations, so as not to scratch the cylinder mirror.
- 🔒 Use the locking tool that comes with the motor (if any)
- 🧵 Rope method: enter a soft synthetic rope into the candle hole and slowly rotate the shaft to the end
- 🚫 Avoid using metal bars through the candle hole - high risk of piston piston piston
Once you've fixed it, you can finally unscrew the central nut. If the nut doesn't unscrew, don't use excessive force that can break the stopper. You'd better heat the nut with a building hair dryer to about 100 to 120 degrees to expand the metal and break down the oxides.
⚠️ Attention: When using the rope fixation method, never try to spin the motor with a starter! this will result in a hydraulic shock or the destruction of the piston group.
Once the nut is removed, inspect the carvings on the shaft. If there are bullies or sticky metal on it, gently clean them with a small file or sandpaper. Smooth thread is necessary for the proper operation of the filmmaker.
Technology of removing flywheel from the cone
The process of removing a flywheel from a cone landing requires the use of a special detacher. Most outboard motors design implies that the flywheel sits on the shaft very tightly due to a Morse cone or similar profile, and trying to knock it down with a hammer on the shaft will cause you to damage the crankshaft bearings or the shaft itself.
Set the tenant so that its paws securely capture the flywheel from the inside (usually there are special holes or protrusions). The central screw of the tenant should rest strictly on the end of the crankshaft. If the tenant rests in a veneer or other detail, you risk tearing the thread or breaking the tool.
☑️ Flywheel removal algorithm
Start to smoothly twist the center screw of the removable with a key, you hear a characteristic click or feel a sharp jump of effort — this means that the cone has left the engagement, at which point the flywheel can go off with a little effort.
If the flywheel is not removed even with considerable effort, do not drag the tenant to breakage. In such cases, it helps to lightly tap the hammer on the end of the shaft (through a soft pad) or on the outer clip of the flywheel during tension of the tenant. Vibration helps to destroy the oxides that hold the cone.
| Motor type | Moment of nut tightening (Nm) | The diameter of the thread (typical) | Features of the removal |
|---|---|---|---|
| Yamaha 2T (5-15 hp) | 64 Nm. | M12 / M14 | Often requires a filmmaker with wide paws |
| Mercury 4T | 95 Nm. | M16 | The generator pulley must be removed. |
| Tohatsu (all models) | 75-90 Nm. | M14 / M16 | Carefully check the veneer when removing |
| Parsun / Hidea | 60-80 Nm. | M12 / M14 | The standard Yamaha filmmakers are often used. |
Diagnostics of elements under the flywheel
After the successful removal of the flywheel, access to important nodes of the ignition and lubrication system is provided. If you've been removing a flywheel to replace an osteoil, now is the time to carefully remove the old seal without damaging the seat.
Carefully examine the veneer (pin) connecting the flywheel and the crankshaft. It should sit tightly in the groove and have no signs of crumpling. If the veneer is "licked" or has a backlash, this will lead to shifting of the ignition phases and unstable operation of the engine at high speeds. If necessary, replace the veneer with a new one.
Also check the status. stator-coil The magnets should not be chipped, the coil should show signs of overheating, melting or breaking the insulation, and the presence of metal shavings on the magnets indicates that the bearing may have collapsed.
Why do magnets lose their power?
A strong heat or mechanical shock can partially demagnetize the permanent magnets of the flywheel, which will lead to a slight spark and problems with starting.
Clean the crankshaft cone and the flywheel's inner cone surface of oxides and dirt, use fine sandpaper (zero) or scotch bright, and perfectly clean contact surfaces will ensure proper fit and heat sink.
Assembly of the knot and installation of the flywheel back
The flywheel is re-installed, but with important nuances in mind. Before installation, lubricate the working surface of the osbium and the cone of the shaft with a thin layer of motor oil or lithium lubricant, which will make it easier to land and prevent a dry start on the first run.
Carefully put the flywheel on the shaft, aligning the veneer groove. Make sure the flywheel sits to the end of the hand. If it doesn't sit down, don't hammer it with a hammer, check the position of the veneer and the purity of the cone. After installation, tighten the nut from hand to end.
The final nut tightening is done with a dynamometer key with the force specified in the manual (manual) for your engine model. An unwound nut will cause the flywheel to turn and the veneer to be cut, and the twisted one can damage the shaft thread.
- 🔧 Tighten the nut to the nominal moment (see table above)
- 🔌 Connect all electrical connectors and check the reliability of the contacts
- 🧪 Start the engine and check for no vibrations or extraneous noises
⚠️ Attention: After assembly, be sure to check the angle of ignition advance (UZ) and the operation of the spark formation system, since the displacement of the flywheel even by one tooth of the strands changes the engine.
The final step is to install the safety casings and test start, and if the motor is running smoothly, without ignition gaps or vibrations, the procedure can be considered successful, and regular checks on the condition of this unit will prolong the life of your outboard motor.
The main secret of successful assembly is the cleanliness of cone surfaces and the use of a dynamometer key when tightening the nut.
What if the flywheel is not removed even by the filmmaker?
If the tenant is stuck and the flywheel is standing, try to warm up the central part of the flywheel with a building hair dryer. Aluminum will expand faster than the steel shaft, and the tension will ease. You can also try to gently tap the hammer on the end of the shaft (through a copper squat) during the tension of the tenant.
Do I need to change the slack every time I take off?
No, the veneer changes only if it's deformed, has crumpled or backlashes in the groove, and if the veneer sits tight and is not damaged, reuse is allowed.
Can I use graphite lubricant for a cone?
It is not recommended to use graphite lubricant on flywheel cone joints, as it can disrupt the landing density, it is better to use pure engine oil or a special assembly lubricant recommended by the manufacturer.
How do you know if the oil is running under the flywheel?
Signs of leaking oil oil are oil stains around the flywheel, oil entering the combustion chamber (blue smoke from the exhaust) or, conversely, air suction, which impoverishes the mixture and causes the piston to overheat.