Buying a new outboard motor is always a joyful occasion for the boat owner, promising many hours of exciting fishing and cruising. However, in order for the power unit to serve faithfully for many years, it needs the right commissioning, known as a break-in. Neglecting this stage or disrupting technology can lead to piston group bullies, overheating and a significant reduction in the life of the engine, even if it is a reliable model with a capacity of 9.9 horsepower.
The laundry process cylinder-piston group Unlike car engines, which are often assembled with surfaces already treated, two-stroke outboard motors need to manually form the perfect gap between the piston rings and the cylinder walls. compression and the tightness of the combustion chamber in the future.
In this article, we will discuss all the nuances of fuel mixture preparation, operating modes at various stages and typical beginner mistakes. You will learn why you can not immediately give full gas and how to properly cool the engine on land if you can not immediately get on the water. boat-engine.
Preparation of fuel mixture and technical liquids
The foundation of successful break-in is high-quality fuel and the right ratio of gasoline to oil. For two-stroke engines with a capacity of 9.9 hp, manufacturers most often recommend a ratio of 1:50 (per 1 liter of oil 50 liters of gasoline) or 1:25 for the first tanks, if in the instructions for a particular model. Yamaha, Tohatsu or Honda The use of poor quality oil or old gasoline can lead to the formation of sodium and exhaust windows.
Only fresh AI-92 or AI-95 gasoline with the octane number recommended by the manufacturer should be used. Old fuel that has been in the canister for more than a month loses its properties and can cause detonation, which is critical for a new engine. two-stroke It is labeled TC-W3, as it has the necessary lubricating properties and the ability to burn without residue.
⚠️ Warning: Never use engine oil for four-stroke motors or dry-case motorcycle oil, which will cause resin deposits to form and cause crankshaft bearings to fail.
Thorough mixing is another important aspect of preparation: it is not enough to just pour oil into the tank and add gasoline; the mixture must be actively shaken or stirred with a clean wooden stick. If the oil settles to the bottom, clean gasoline will go into the cylinder, which is guaranteed to cause a clean, clean, tidal gas. bully and overheating.
Use a measuring cup or a special oil syringe to keep an exact proportion. It is almost impossible to determine the amount of oil in a large canister of gasoline by eye, and an error in dosage is dangerous for the engine.
First start and idle operation
The first start of the new engine is best done on land, using a water barrel or a special cooling system, if any, which will allow you to monitor the engine, listen to sounds and check the cooling system without the risk of winding the grass on the screw. Before starting, make sure that the fuel hose is connected, the pump pear is pumped, and gaskle It's in the starting position.
After successful start-up, let the engine run at idle speeds for 10-15 minutes, during which time the primary distribution of oil to all friction nodes occurs. Carefully monitor the jet of water coming out of the control hole: it should be flat and pulsating. The absence of a water jet even for a short time threatens instantaneous overheating and deformation. blockhead.
At this point, it's important to listen to the engine, and a smooth, confident sound without claps or dips indicates that the carburetor is properly adjusted (if it's not electronic) and the intake tract is tight. If the motor stalls when trying to add gas or is unstable, you may need to adjust the carburetor. quality and quantity of screws.
- 🌊 Check the tightness of fuel connections and the absence of air suction.
- 🔊 Listen to the sound of the exhaust: it should be smooth, without sharp claps.
- 💧 Make sure that the thermostat (if designed) starts to open and let water in a large circle.
If you're running in a barrel, watch the water level. It shouldn't be too low for the pump to take in air, but it shouldn't be too high for the candle or the splash ignition system to fill. water-hole at least 10-15 cm in lower unit.
breaking in modes: time and revolution table
The most critical phase is the first 10 hours of operation, and it's during this period that the piston rings are basically latched to the cylinder mirror, and the disruption of the operating modes during this time is impossible to compensate for in the future. Modern 9.9 hp engines require a phased increase in load, allowing the metal to expand and take shape without critical friction.
Usually, the process is divided into several stages: the first hours are at speeds below 50% of the maximum, then the load gradually increases. It is important to understand that "full gas" in the first 10 hours is strictly forbidden. The engine must operate in a gentle mode so that the micronervities on the friction surfaces smooth out, not strip.
Below is a typical table of break-in modes for two-stroke engines with a capacity of 9.9 hp Please note that for some models Suzuki or Mercury The recommendations may vary slightly, so always check with the manual.
| Working hours (hours) | Throttle mode | Maximum loading | Recommendations |
|---|---|---|---|
| 0 - 1 hour | Idle move | 0% | Work on land or in a barrel, checking systems |
| 1- 2 hours | Up to 1/4 open. | 25% | Moving at minimum speed, avoiding planing |
| 2 - 8 hours | Up to 3/4 open. | 75% | Periodic acceleration, planing for a short time |
| 8 - 10 hours | Full discovery | 100% | Short-term acceleration to full gas (no more than 2 minutes) |
It's important to keep the throttle in one position for too long. Revs help to spread the load evenly and improve the lubrication of all the knots. If you feel the motor is starting to lose power or you hear a ringing, immediately release the gas and check the cooling system.
Running on water: features and nuances
Getting to the water after pre-launch on land is a transition to real-world operating conditions, and there are many factors that come into play: propeller load, water resistance, ambient temperature and fuel quality. In the first hours, try to choose calm water without strong wind and wave, so as not to create an excessive load on the water. graffiti and lower unit.
Avoid sharp jerks with a handle of gas when you're driving, and the smooth addition of turns allows the oil to effectively lubricate rubbing vapors. gellingDo this only after the engine has warmed up to operating temperature, and a cold engine is not able to provide the necessary thermal clearances.
⚠️ Attention: Avoid long-term work in one mode. Alternate the movement on the glides with the transition to displacement mode. This will prevent local overheating and promotes uniform laundry of the rings.
Pay special attention to the position of the lower unit. When running, the engine often runs at higher speeds, and if the boat goes with a differentiator on the nose, the water intake can become bare, which will lead to air sucking into the pump and instantaneous cessation of cooling. differentiation boats by moving a load or changing the angle of the motor.
☑️ Controls for running in water
After every 2-3 hours of operation, it is recommended to take a break. Let the motor cool down, inspect it for fuel or oil leaks, check the tightening of the lower unit mount bolts to the intermediate bowl. Vibration in the first hours can weaken the threaded joints, and they need to be tightened.
Typical errors in engine running
Many owners, wanting to test new technology faster, make fatal mistakes that negate the entire life of the engine, the most common of which is working at full gas from the first minute. two-stroke.
Another mistake is to use a rich mixture (too much oil) in the hope of better lubricating the engine, and the excess oil doesn't burn out completely, forming a stain on candles, pistons and exhaust, which causes compression to fall and it's difficult to start, and the candle becomes covered with a black velvety coating and stops sparkling.
- 🚫 Ignoring warming up: Trying to put a load on a cold engine right away.
- 🚫 Work in the "traction": movement with a heavily overgrown propeller or on a boat too heavy.
- 🚫 Use of old fuel: oxidized gasoline causes detonation and coking.
It is also a mistake to neglect the quality of spark plugs. Even on a new engine, it is better to immediately check the gap on the candle and its condition. Often in new engines, candles with defective or incorrectly exposed gap can occur, which affects the quality of combustion of the mixture during a critical period. laundry.
What happens if you don’t change the oil in the gearbox after running?
In the first hours of operation, the gearbox can produce fine metal shavings from laundry gears, and if you don't replace the oil after the first 10 hours, this shaving will act as an abrasive, accelerating wear on the bearings and gear teeth.
Completion of break-in and first maintenance
After winding the first 10 hours (or the volume specified in the instructions, for example, 20 hours for some models), the break-in is considered complete. However, this does not mean that you can forget about the engine.
First of all, you need to replace the oil in the gearbox. As mentioned above, there may be shavings. It is also recommended to replace the spark plugs with new ones, since the old ones already have a soak and a changed gap. Checking and lifting all bolt joints, especially the fastenings of the lower unit and carburetor, is mandatory.
After the maintenance, the engine is considered fully ready for use in any mode. Now you can safely use full power for water skiing or fast travel. However, remember that careful treatment and use of quality fuels will prolong your life. boat-engine for thousands of motor-hours.
The first maintenance after running is a prerequisite for maintaining the warranty and long service of the engine. Do not ignore the change of oil in the gearbox and candles.
Frequently Asked Questions (FAQ)
Can I run the engine 9.9 hp without getting on the water, only in a barrel?
Theoretically, you can spend the first 1-2 hours in a barrel, but full break-in requires a load on the screw. In a barrel, you can't simulate the resistance of water that the screw experiences when moving. Therefore, for high-quality laundry of the rings under load, you need to go to water.
Which oil is better to use for running: mineral or synthetic?
For two-stroke engines, it is better to use high-quality semi-synthetic or special mineral oils labeled TC-W3. Synthetics may be too slippery for the primary grinding process, although modern oils allow its use, the main thing is that the manufacturer meets the specification.
Do I need to change the proportion of the mixture during the break-in?
Some of the old instructions recommended that you make the mixture richer (more oil) in the first hours. Modern 9.9 hp engines require you to follow the standard ratio (usually 1:50) at all stages. Increase the amount of oil will only lead to soot. Follow the instructions to your particular model.
What if the engine starts to stop during the break-in?
Don't panic. Let the engine cool. Check the fuel filter for water or dirt. Check the candle, if it's wet and black, it may be too rich or the air filter is clogged. If the problem recurs, contact the service center without continuing to operate.