Buying a new one two-stroke With 9.8 horsepower, it's a milestone for any boat owner to start the active navigation season, but to keep it going for years and enjoying a steady thrust, it's critical that you don't go out to the water right after you buy it at full capacity. The burnout period, or break-in, is a must-do phase, and ignoring it can lead to piston group bullies and loss of warranty.
The process of grinding rubbing parts requires strict adherence to the temperature regimes and proportions of the fuel mixture. Unlike four-stroke analogues, two-stroke 9.8 hp engines are lubricated with oil added directly to gasoline, making the quality of preparation of the mixture and the modes of operation in the first hours of operation determining factors of durability. crankshaft and bearings.
In this article, we will discuss in detail all the stages of preparation, from the first start in a barrel to the exit to full gas in open water, you will learn why you can not keep the engine at idle speeds for too long and how to calculate the correct amount of oil for the engine. fuel-mix depending on the stage of the break-in.
Preparation of fuel mixture and technical liquids
The foundation of successful break-in is a properly prepared fuel mixture. For two-stroke engines with a capacity of 9.8 hp, AI-92 or AI-95 gasoline is usually paired with a quality synthetic oil, specifically designed for the use of gasoline. outboard motorsThe standard ratio for new motors is often 1:25 or 1:50, but during the break-in period, many manufacturers recommend enriching the mixture, that is, making it slightly richer in oil for better lubrication.
Only fresh gasoline with a shelf life of less than 30 days should be used, as old fuels lose their octane properties and can cause detonation. carburetor.
⚠️ Warning: Never use motor oils for cars or cheap mineral oils in a two-stroke outboard motor, which will lead to candles and tail windows coking, which will require expensive repairs.
In addition to fuel, attention should be paid to the transmission oilBefore the first run, be sure to check the oil level in the gearbox through the control holes. It should be transparent and fill the entire volume of the gearbox to the upper hole.
Use a measuring cup with a gradation, coming with the motor or bought separately, so as not to disturb the proportion of mixing even by 10-20 ml.
First start of the engine in a tank with water
The initial launch of the new unit is strictly forbidden to be carried out "dry" or in air without diving the lower unit. The lack of water cooling instantly overheats engine, causing thermal expansion of aluminum alloys and jamming of the piston. This stage will require a barrel or a special barrel-sludge tank filled with water at least 2/3 of the height of the lower unit.
Place the motor on a tray or in a barrel, making sure the water intake holes are fully submerged. Open the fuel faucet, press the fuel pump pear several times until it is solid, and pull out the handle. starterAfter starting, let the engine run at idle speeds for no more than 3-5 minutes.
At this time, carefully observe the stream of water coming out of the control hole (piss-hole). impeller (water pump) and no air traffic jams in the cooling system. If the water is not coming, immediately turn off the engine to avoid overheating.
- ✅ Check the tightness of fuel connections and the absence of air suction.
- ✅ Make sure the motor confidently keeps idling revolutions without deafening.
- ✅ Listen to the engine: foreign knocking or screeching is unacceptable.
- ✅ Check the Forward-Neutral-Reverse system.
breaking in stages: table of operating modes
The process of running in is divided into several time intervals, each with its own speed and load limitations, the main goal being to ensure that piston rings are evenly applied to the cylinder walls and crankshaft bearings, and that breaking the sequence of steps can negate all maintenance efforts.
The first hours of operation should be in a gentle mode. You should not immediately give full load. The 9.8 hp engine has a sufficient power reserve, but it is not necessary to give it a full load. mechanical-assemblies The following table shows the operating modes according to the motor clock.
| Working hours (motor clock) | Throttle mode | Recommended proportion of oil | Action |
|---|---|---|---|
| 0 - 1 hour | Idle move | 1:25 (or according to instructions) | Warming up, checking systems, working in a barrel |
| 1- 3 hours | Up to 30-40% gas | 1:25 | Low speed movement, avoiding planing |
| 3 - 8 hours | Up to 60-70% gas | 1:30 - 1:40 | Exit to glysing short-term, variable loads |
| 8 - 10 hours | Up to 80% gas | 1:50 (standard) | Active operation, avoiding full throttle |
| 10+ hours | 100% (short term) | 1:50 (standard) | Normal operation, periodic accelerations |
⚠️ Attention: It is strictly forbidden during the first 10 hours (long) to work at constant speeds, whether it is idling or full gas. Vary the load so that the rings are worked on the entire surface of the cylinder.
Operation on water: the first hours of the journey
After a successful barrel run, you can go to water testing. For a 9.8 hp engine, it's important to get the right screw and load. It's best to spend the first hours in calm water without strong wind and current. load variability.
Keep the gas handle in one position. Add gas periodically to make the engine go to the planing, and then drop to a minimum. This "teared" work contributes to better lubrication of all the knots and uniform distribution of the oil film. Avoid long idling, because in two-stroke engines at low revs, lubrication may be insufficient due to the specifications of the carburetor.
Watch the engine temperature by feeling the casing (carefully not to get burned) it should be warm, but not hot. If the casing cannot be held with your hand for more than 2-3 seconds, then the engine is overheating, and you should drop the gas or check the cooling system.
☑️ Control during water break-in
Pay special attention to gear shifting. Turn on the front and reverse only after the gas is discharged to idle. switch-over Or cutting gears.
Control of temperature and cooling system
The two-stroke 9.8 hp engine is cooled by off-board water that passes through the cooling shirt. During break-in, the temperature must be monitored especially carefully, overheating leads to deformation of the cylinder head and burnout of the piston, and underheating leads to violation of thermal gaps and increased wear.
The optimum temperature is about 40-50 degrees Celsius for warm-up and up to 80-90 in operating mode. The thermostat (if designed by your model) should open when you reach a certain temperature, launching water in a large circle. Until then, the water circulates in a small circle for rapid warming.
What to do if a water stream is missing?
If you notice that the control jet of water has disappeared or has become very weak, immediately release the gas to a minimum. Don't turn off the engine immediately if it's hot - let it work for idle for a couple of minutes, but watch the temperature. Most often the cause is algae that clogged the water intake, or damage to the impeller. Lift the motor, clean the holes and check the pump.
So when you're driving at low speeds, you're more likely to overheat, and if you're planning to go at trolling speed for a long time, make sure that the cooling jet is stable.
Completion of break-in and first maintenance
After the first 10 hours of running (or 2-3 fuel tanks, depending on the conditions) are used, the break-in stage is considered complete, but this does not mean that you can forget about the engine. maintenance for the lifetime of the engine.
You need to replace the oil in the reduct, even if it looks clean. In the first hours of operation, the products of the grinding of the gears may appear in the oil, and it is also recommended to check the tightening of all bolt joints, since the vibration during the break-in could weaken the fastener.
- 🔧 Replace the oil in the gearbox.
- 🔧 Check and replace spark plugs if necessary (the lozenge should be brick-colored).
- 🔧 Blow the carburetor and check the idling settings.
- 🔧 Lubricate all lubrication points (pivot hinges, gas cable) with lithium lubricant.
⚠️ Attention: When tightening the bolts of the lower unit and attaching the motor to the transom, use a dynamometer key. The drag can lead to a failure of the thread in the aluminum alloy, and the tightness to vibrations and destruction of the knots.
The first maintenance after 10 hours is critically important: it is at this moment that the products of primary wear are removed, and the engine goes into normal operation mode with an increased resource.
Typical errors in breaking in
Many owners, in their quest to test new technology faster, make mistakes that can cost the engine a resource, and the most common of them is constant revs. Owners often think that if they go smoothly at average speed, it's good. piston-group Short-term acceleration and braking of the engine is more useful.
Another mistake is the use of old or poor-quality fuels: the ethanol found in modern gasoline can absorb moisture from the air, which leads to dissection of the mixture and corrosion of the carburetor. Always use fuel stabilizers if the engine will be without work for more than two weeks.
Also, they often ignore the need to warm up before loading. Starting the engine and immediately full gas is the right way to get bullies. Let the oil spread to all the nodes, warm up the engine for at least 2-3 minutes on idles.
Keep an onboard log or simply write down the motor watch and operations on your phone, which will help you remember about timely maintenance and will be useful when selling a boat in the future.
Frequently Asked Questions (FAQ)
Can I run the engine 9.8 hp on land, connecting the hose?
Driving on land through an adapter (the ears) does not provide the full cooling of the lower unit and exhaust system as well as immersion in water, and you can not test the engine under real load of the screw. Use the barrel only to check the start, but not for full break-in.
Which oil is better to use for running: mineral or synthetic?
For modern two-stroke 9.8 hp engines (Yamaha, Tohatsu, Mercury, Hidea) semi-synthetic or synthetic oils with a tolerance of TC-W3 are best suited. Mineral oils can leave more soak, especially if the proportion of the mixture has been disturbed towards enrichment. Synthetics provide better lubrication at high temperatures and burn cleaner.
Do I need to change the candles after the test?
Preferably, during the break-in, candles may form a specific scent due to the rich mixture, replacing candles with new ones after the first 10 hours will ensure stable spark formation and easy start later, old candles can be cleaned and used as spares.
What if the engine stops when you add gas?
This may indicate that the carburetor is not properly set up (the mixture is too poor) or that the ignition system is not working properly. During the break-in, the mixture should be slightly richer. quality and quantity of screwsDon't try to spin the carburetor yourself without experience.
How long does it take to complete the process?
The full exhaustion of all the nodes of the two-stroke engine takes about 10-15 motor hours, but it is recommended to observe a gentle operating mode for the first 50-100 hours or the first season, only after that you can operate the engine at 100% of its power in extreme conditions.