Choosing a power plant for a boat or a boat is always a compromise between power, efficiency and reliability. Yamaha 100bhp. It has been a leader for decades, and it is the power to plane a 4 to 6-meter long craft with a seamless speed and efficient fishing experience that Yamaha engineers have been able to introduce technologies previously available only to flagship models.
Why 100 forces? That's the threshold where the amateur level ends and serious navigation begins. Yamaha F100 or its two-stroke predecessors of the series 90-100 Not only are they numerically rated, but they are particularly thrust-prone at low speeds, and owners of these units often note that the engine pulls the boat even when it is fully loaded and excited, which is critical for water safety, and this class of engines is often the last step before switching to a V-shaped configuration, while remaining in the format of a row four.
Modern environmental and noise requirements dictate their rules, and the Japanese company has successfully adapted its best-selling engines. four-stroke But to make sure you don't make the mistake of buying used appliances or choosing a new model, you need to understand the technical details, which we'll discuss in detail below, and understanding the device will help you avoid expensive repairs in the future.
Specifications and engine design
The heart of any 100 horsepower model is a cylinder block. Yamaha F100, using a classical scheme four-cylinder The cylinder volume is usually about 1832 cubic centimeters, which provides the optimal ratio of the piston stroke to diameter, and this arrangement ensures excellent balancing and minimal vibration even at high speeds of the shaft.
The power system has also undergone a major change, and early models could have carburetors, but today the de facto standard has become the carburetor. fuel-injection This allows the motor to respond instantly to changes in load and ambient temperature, the fuel mixture is prepared with surgical precision, which directly affects exhaust purity and efficiency, and the combustion processor uses a microprocessor unit to control the combustion processes, which constantly optimizes the angle of ignition.
⚠️ Attention: When operating engines with EFI system, it is extremely important to use only high-quality fuel with an octane number of at least 95. The use of low-octane gasoline can lead to detonation, which can destroy the piston group in a matter of minutes under load.
The engine is cooled by off-board water through a rubber impeller pump. The thermostat maintains operating temperatures within a strictly defined range, usually around 50-60 degrees Celsius, which is necessary to efficiently lubricate and minimize wear of rubbing parts. The exhaust system is implemented through the propeller hub, which also contributes to noise reduction.
Yamaha's Technical Secrets
How does Yamaha achieve such reliability?: The secret lies in the anti-corrosion coating of all internal parts of the engine and the use of stainless steel for the exhaust system. In addition, the pressure lubrication system delivers oil to all critical components, not just spraying.
Two-stroke vs. four-stroke: which one to choose?
On the secondary market, you can still find two-stroke models of the series. Yamaha E100 or 90-100 HPThey are much lighter than their four-stroke counterparts and easier to transport. However, their design requires the preparation of a fuel mixture (gasoline + oil) or the presence of a separate lubrication system, which increases fuel consumption and the level of toxicity of the exhaust. boat-engine It has a more sound and high reception at the start.
Four-stroke units, such as the series F100They're more complex and heavier, but they offer a number of undeniable advantages: they don't require fuel mixing, they work quieter and they use 30-40% less gasoline at the same speeds. The resource of a four-stroke before a major overhaul is usually twice as high as that of a two-stroke counterpart. four-stroke It is an uncontested choice.
If the transom of the PVC boat is designed for 80-90 kg, then a heavy four-stroke may require the installation of additional inflatable tubes or transax reinforcement. In the case of metal or fiberglass boats, the weight of the engine in 150-170 kg does not play a decisive role, and here the priority is comfort and economy.
Fuel consumption and efficiency of operation
One of the main questions that a potential owner is concerned about is how much the engine eats gasoline. For the 100-horsepower Yamaha, the average consumption at full gas (Wide Open Throttle) is about 35-40 liters per hour. However, in real mode, at a cruising speed (about 4000-4500 rpm), the consumption decreases to 20-25 liters. This makes the engine quite economical for its class.
The economy is directly affected by the condition of the propeller and bottom of the boat. A shelled bottom or damaged propeller can increase fuel consumption by 15-20%. It is also important to choose the right pitch of the propeller. Too much stride will make the engine run in overload mode, and too small will not allow you to get on plane, causing the engine to roar in vain.
| Mode of work | Turnover (rpm) | Speed (km/h)* | Expenditure (L/h) |
|---|---|---|---|
| Idle move | 900 | 5-7 | 1.5 - 2.0 |
| trolling | 2500 | 15-20 | 8.0 - 10.0 |
| Cruiser | 4500 | 45-50 | 22.0 - 25.0 |
| Full gas. | 6000 | 60+ | 38.0 - 42.0 |
* Speed is indicated for a boat with a length of 5 meters with two passengers. As you can see from the table, the main consumption is when you're driving at maximum speeds. For anglers who are trolling or anchoring most of the time, 100 liters of fuel will be enough for a day of active fishing.
For maximum fuel economy, try to keep your speed in the torque range (usually 3,500-5000 rpm).
Maintenance and resource of the motor
Japanese engineers are famous for their meticulousness, and Yamaha 100 hp The engine can last well over 3,000 hours, and the key to longevity is to change the engine oil on time, and in four-stroke models, this should be done every 100 hours or once a season, whichever comes first.
Special attention should be paid to the cooling system. After each trip through salt water, the engine must be washed with fresh water. Salt causes corrosion that can destroy the water jacket of the cylinder block. Also regularly check the water control hole ("urinal"): if the jet is weak or intermittent, then the impeller pump is worn out or clogged cooling channels.
☑️ Seasonal engine maintenance
The spark plugs in electronic injection engines last longer, but they need to be monitored. Black colored paint indicates a rich mixture or ignition problems, white plaque indicates overheating or poor mixture, normal color of the electrode is brick-brown, and also remember to change fuel filters, especially if you refuel at untested gas stations.
⚠️ Attention: Never store a full-bore engine during the winter without adding a fuel stabilizer. Modern ethanol gasoline is prone to stratification and the formation of resinous deposits that can coke fuel injectors.
Common malfunctions and methods of their elimination
Despite its high reliability, the machinery is not immune to breakdowns, and one of the common problems owners face is difficulty starting or unstable operation at idle speeds. throttle Cleaning these nodes with special aerosols often solves the problem without going to the service.
Another common problem is the ingestion of water into the oil, and if the oil in the crankcase has acquired the color "coffee with milk", it is a signal that the gasket of the block head is broken or the heat exchanger is damaged, and it is strictly forbidden to operate the engine in this state, as this will lead to the twisting of the liners and the bullying of the cylinders.
Electrical problems also occur, especially on long-range motors, oxidation of the contacts in the suspension harness or a malfunctioning stator can cause the spark to disappear, and diagnosis begins with checking the voltage on the candle tips and visually examining the wiring for rubbing.
90% of engine start and operation problems are related to fuel quality and spark plug condition, and always start your diagnosis by checking these components.
Selection of screws and compatibility with boats
For a 100 hp engine, the right propeller is critical. The standard solution for most 4.5-5.5-meter boats is a 15-17-inch propeller. If the boat is heavy or you plan to ride full load, it makes sense to put a smaller propeller (13-14 inches) so that the engine can gain working speed.
The engine is perfectly combined with PVC inflatable boats (NPVC) up to 5 meters long, as well as aluminum "Kazanki" and fiberglass boats of the "Crimea" or "Ob" type (with restrictions on the height of the transom). It is important that the height of the engine is in line with the manufacturer's recommendations, otherwise cavitation and overheating are possible.
When choosing a screw, pay attention to the material. Aluminum screws are cheap and easy to recover, but they are less efficient at high speeds. Stainless screws (series) Yamaha Performance) provide better acceleration dynamics and maximum speed, but they are more expensive and can transfer the load to the lower unit when hitting an underwater obstacle.
Next Next post: Should I Buy a 100 HP Yamaha?
In summary, it can be said that Yamaha 100 hp The combination of time-tested design, spare parts availability and high liquidity in the aftermarket makes this one of the best investments for a boating, it forgives minor errors in operation and is able to run for years with minimal maintenance.
If you're looking for a reliable workhorse for fishing, family or water tourism, this motor is a great choice. It provides enough power to plane confidently, while still being quite economical. The main thing is not to save on maintenance and quality consumables.
What is the best octane gasoline to fill in the Yamaha 100?
The manufacturer recommends using gasoline with an octane number of at least 95 (according to the research method, RON). The use of 92nd gasoline is possible only in emergency situations and at low speeds, but use will lead to detonation and power reduction.
How much oil do you need in the gearbox?
The volume of oil in the gearbox depends on the specific model of the daydvut, but on average is about 300-400 ml. Level control is carried out through the bottom drain hole: oil should appear from it when the outboard motor is in an upright position.
How often do I change the water pump?
Replacement of impeller water pump is recommended every 300 hours or every 3 years, even if there are no visible problems. rubber over time tans and loses elasticity, which can lead to sudden overheating at the most inopportune moment.
Can I transport the motor on the side?
Transportation on the side is possible, but only in a certain position (usually on the right, if you look from the back) and no more than 20-30 minutes. Prolonged transport or storage on the side of the oil leaking into the cylinders (for four-stroke) or fuel mixture in the crankcase (for two-stroke).