Choosing an outboard motor for a boat is always a balance between power, weight and economy. When it comes to a 50 horsepower class, many aquatic motorists turn their attention to the products of the Japanese corporation Honda. This is a borderline power that already allows you to glid confidently on boats with a length of 4-5 meters, but still allows you to operate the vessel without mandatory registration with GIMS (in some configurations and with a certificate). Four-stroke technology This is not just a marketing move, but a real advantage for those who appreciate the silence and purity of the exhaust.
Honda’s 50-horsepower range is traditionally known for its “unkillability” and clever engineering. Unlike its two-stroke counterparts, these engines do not require a fuel mixture and run on pure gasoline. However, potential buyers are often confused by the weight of the unit and the more complex design. Should we overpay for the brand and environmental friendliness? Let’s see what is hidden under the jacket. Honda BF50 And the engine, and the modifications, and who really should invest in that engine?
It's important to understand that 50 hp is a threshold value. For lightweight aluminum boats, it's often the maximum allowable power, and for heavier hulls, it's the minimum required to go into mode. A key feature of Honda in this class is the PGM-IG (Programmed Ignition) system, which provides accurate electronic ignition without the need for manual adjustment of gaps. This directly affects the stability of idling and fuel consumption, which is critical for long fishing outlets.
Technical specifications and design features
The design of the Honda BF50 is based on the time-tested cylinder block used in many models of the manufacturer. The engine has 4 cylinders arranged in a row, which ensures excellent balancing and vibration reduction. The engine volume is 722 cc, and the SOHC gas distribution system (one camshaft) ensures reliable valve operation. The weight of the engine as standard is about 92-95 kg, which is typical for 4-strokes of this power, but significantly heavier than two-stroke competitors.
The cooling system is built on a classic scheme with forced circulation of water through the water pump, and engineers have focused on a thermostat that allows the engine to quickly reach operating temperature, reducing the wear of parts when warmed up. The exhaust system "through the screw" not only reduces noise, but also reduces water resistance when driving, increasing overall efficiency. Fuel system It is equipped with electronic injection or carburetor (depending on the year of production and modification), which makes the engine less sensitive to fuel quality compared to modern injection systems of competitors.
The gear ratio is usually 2.08:1, which is the optimal balance between thrust and speed. High-Thrust screws (with increased pitch and diameter) are often included or available as an option, allowing for better push of heavy boats. The reliability of the gearbox is confirmed by decades of operation in salt water, subject to regular grease replacement.
Below is a summary table of the main technical parameters that will help compare the Honda BF50 with its counterparts:
| Parameter | Meaning |
|---|---|
| Power | 50 hp (36.8 kW) |
| Engine capacity | 722 cm |
| Number of cylinders | 4 (in row) |
| Weight (with screw) | ~95 kg |
| Launching system | Electrical starter/Manual |
Advantages of Honda’s four-stroke system
Honda’s top priority is efficiency. The four-stroke combustion cycle allows fuel to be used more efficiently, burning it completely. Owners note that at cruising speeds (about 30-35 km/h), fuel consumption is approximately 15-18 liters per hour, which is significantly less than two-stroke engines of similar power, which can “eat” 20-25 liters. For fishermen who spend all day on the water, this is a significant budget savings.
The second big advantage is that it's green and clean, and the lack of oil in gasoline means that the exhaust is cleaner, and the water at the back is not rainbow-filmed, which is especially important for those who fish in protected areas or just care about nature. smoke-free It makes the boat more comfortable, especially if the wind blows towards the cockpit.
The third aspect is durability and resource. With a separate lubrication system (cartwheel oil) in place, the rubbing parts are always in the oil bath or under pressure. This reduces the wear of the piston group and crankshaft bearings. Honda motors are known for running thousands of motor hours without major repairs when oil is replaced on time.
⚠️ Attention: Despite its reliability, the four-stroke motor cannot be transported on the side or upside down without first draining the oil from the crankcase. The oil can enter the combustion chamber through the valve, which will lead to hydraulic shock at start-up and serious engine failure.
Fuel consumption and economic efficiency
Fuel consumption is often a crucial issue when choosing between 2T and 4T. The Honda BF50 is doing well in this regard thanks to Lean Burn combustion technology (in some versions) and the fine tuning of the carburetor. At idle speed, the engine consumes less than 1 liter per hour, allowing hours of drift at the catch point without fear of emptying the tank.
When you get on plane, you get a sharp increase in flow, but then you stabilize. If a two-stroke engine at full speed can consume fuel in buckets, Honda can keep itself in control, and this allows you to plan long-distance transitions with less fuel on board, which also reduces the overall weight of the boat. Savings It becomes noticeable after the first season of active operation.
Although four-strokes require oil replacement in the gearbox and engine, the lack of need to mix gasoline with oil and less wear of candles (due to cleaner combustion) offset these costs. Honda's spark plug life is much longer.
Use AI-95 gasoline with an octane number not lower than recommended in the instructions. Use of fuel with a low octane number can cause detonation and damage the piston group, and fuel with ethanol above 10% can destroy rubber fuel system seals.
Maintenance and regular maintenance
Regular maintenance is the key to a long life for your engine. For the Honda BF50, it involves several mandatory procedures. The primary maintenance is carried out after the first 20 hours, then every 100 hours or once a year. The engine oil is the first to change, and you need to use specialized oil for four-stroke outboard motors (FC-W standard), which has increased anti-corrosion properties.
The second important element is the lubricant of the gearbox: the oil in the lower block is usually changed once a season or every 100 motor hours. When replacing, be sure to check for emulsion (water) in the waste oil. If the oil is "coffee with milk", then the sealing of the oils is broken and repairs are required.
The cooling system also requires attention. You need to check the control trickle of water regularly, if it is weak or intermittent, it may be clogged water channels or worn out impeller pump. Replacement of the impeller is recommended every 2-3 years, even if the motor is working normally, as the rubber over time tans and cracks.
☑️ Seasonal TO Honda BF50
Comparison with competitors: Yamaha, Tohatsu, Mercury
In the 50-horsepower market, Honda has strong competitors. the Yamaha F50 is often compared to Honda in reliability, but the Japanese competitor can be a little heavier and more expensive to maintain due to the design of the head of the block. Tohatsu (which, incidentally, makes engines for the Mercury) offers excellent traction and often more affordable price, but Honda benefits in terms of quiet operation and smoothness.
The Mercury 50 EFI (injector) will be more economical than a Honda with a carburetor, but more difficult to repair in the field. The Honda carburetor is easier to diagnose and repair on the knee with a minimum set of tools. For remote regions and expeditions, this can be a decisive factor.
If you look at the used market, Honda is better at price than most, which means that there's a lot of demand and confidence in customers, it's hard to find a live one, but if you find one, it's going to last a very long time, and competitors may want to get more ignition or fuel system interventions.
The secret of Honda's popularity
Why is Honda so valued? It's not just the engine, the corrosion resistance of the coatings, the quality of the plastic and the accessories, and the availability of parts even for models 10 to 15 years ago, create the very reputation that customers overpay for.
Typical malfunctions and ways to eliminate them
Despite the high reliability, problems can occur in any mechanism. One of the common problems is overheating. If the temperature sensor gives a signal or the engine dies, the first thing to do is check the water pump. Also, the cause can be low water level (the intake is clogged with grass) or the thermostat that stuck in the closed position.
Start problems are often related to the ignition system or fuel. Older models with carburetors can suffer from clogging of jellyplants if the engine has been with gasoline for a long time. In the ignition system, it is worth checking the coils and candle caps for breakdown (especially in wet weather). Engine rotating (working on 3 cylinders) often indicates a malfunction of one candle or coil.
Noise during the gearbox operation may indicate the production of bearings or gears. If you hear a grinding sound when changing gears, you may need to adjust the gas/reverse cable or replace frictions. Self-repair of the gearbox without experience and special tools is not recommended.
⚠️ Attention: Never attempt to start a motor without a water pump impeller installed or with water intake holes covered, even for a few seconds. Dry friction will instantly destroy the seals and the impeller itself, leading to overheating and jamming.
Operation and storage tips
To keep the engine happy for years to come, follow the simple rules: after each departure in salt water, be sure to wash the engine with fresh water. Don't be lazy to remove the casing and gently water the engine from the hose (not under strong pressure directly on the oil oils and electrics), this will wash away salt, which is the main enemy of aluminum and steel.
When stored in winter, be sure to stabilize the fuel. Add a stabilizer additive to the tank and let the engine run for 5-10 minutes to allow the mixture to pass through the fuel system. This will prevent the oxidation of gasoline and the formation of resins that clog the carburetor. The ideal option is to fully generate fuel from the float chamber.
Keep the motor upright in a dry room. If you can't, use a special stand. When transporting on a trailer, use a transom stop to relieve the load from the transom of the boat and the lower unit of the engine on the bumps.
The main secret to the longevity of the Honda BF50 is not only the build quality, but also the regular change of oil and flushing the cooling system with fresh water after each outing.
What is the best gasoline to fill in a Honda BF50?
The manufacturer recommends using unleaded gasoline with an octane rating of at least 92 (by the research method), but the best choice will be the AI-95. It is important that the fuel is fresh. Do not store gasoline in the engine tank for more than 30 days without a stabilizer, since modern fuels are prone to stratification and sludge.
Can I charge the battery from the motor?
Yes, the Honda BF50 is equipped with a generator (usually 12B, 16A or higher depending on the year) but it is primarily designed to keep the on-board systems (echo sounder, navigator) charged completely dead battery from the motor can be, but it is inefficient and can lead to the discharge of the battery of the motor itself when parked.
How often should you change the oil in the gearbox?
Officially, every 100 hours or once a year, experienced water-engineers recommend doing this more often, for example, in the middle of the season and before wintering, the color of the oil should be transparent or slightly yellowish. The appearance of metal shavings on the magnet cork (in the form of powder) is permissible in small quantities, but large pieces of metal indicate a problem.