Choosing an outboard motor for a small boat or boat often becomes a difficult dilemma, especially when the budget is tight and reliability requirements are high. Mikatsu 20 It has a special place, having established itself as an affordable and hardy "workhorse" for anglers and water lovers. two-stroke The unit attracts attention with its simplicity of design, which makes it understandable even for beginners who first encountered water-motor technology.
The model's popularity is not only due to its low price, but also to its time-tested design, which goes back to classic Japanese designs. boat-engine This brand is great at handling heavy loads and challenging operating conditions on our water bodies, but like any equipment, there are nuances of maintenance and operation that must be considered before buying.
In this article we will discuss in detail the technical specifications, features of running, real fuel consumption and typical problems that can be encountered during operation. Mikatsu 20You will receive comprehensive information that will help you make an informed decision about the purchase of this engine or properly maintain the existing one.
Technical specifications and design features
Engine. Mikatsu M20FHS The 20 horsepower is a classic two-stroke engine with a forced air cooling system (although the water pump itself cools the dead-dude and exhaust gases, thermostating is simplified here). The power of 20 horsepower is the “golden mean” for inflatable boats ranging from 3.2 to 4.0 meters in length and small metal “kazaks”. The engine weight is about 45 kg, making it relatively easy to install and transport in the trunk of a passenger car.
The power unit is built on a proven cylinder block with a piston group, which provides high torque at low revs. This is critical for entering the plane with the boat fully loaded. The ignition system is an electronic CDI that does not require adjustment of gaps and provides a stable spark even when moisture is injected.
⚠️ Warning: Despite the presence of a built-in thermostat in some versions, the cooling system requires regular checks of the control jet, overheating of the piston group on the two-stroke engine is instantaneous and leads to bullies.
An important element is the deidud, in which the transmission This ratio allows you to use the propeller's thrust efficiently, minimizing power losses. The propeller shaft rotates in bearings that require periodic lubrication, which many forget, leading to corrosion and jamming.
Hidden features of the lubrication system
The Mikatsu 20 uses a mixture of oil and gasoline, but the lubrication system for crankshaft and rod bearings depends on the quality of the mixture, and the use of low-quality oil causes rapid wear and tear on needle bearings, which is a hidden but fatal problem for the engine life.
Fuel consumption and efficiency of operation
One of the main issues that concern potential owners is fuelFor a two-stroke engine of 326 cubic centimeters, this parameter is directly dependent on driving style and loading of the boat. On average, at a cruising speed (about 3,500-4000 rpm), the engine consumes approximately 6-7 liters of fuel mixture per hour.
With active planing and full-gas driving (5000-5500 rpm), consumption can increase to 9-10 liters per hour, which is significantly more than modern four-stroke analogues, but the two-stroke circuit provides better acceleration dynamics. carburetor and the quality of the mixture.
- 🛶 At idling, the consumption is minimal and is about 1-1.5 liters per hour, which is convenient for fishing in fermented points.
- ⛽ Optimal saving mode is achieved by 70-80% of the maximum power, where the specific fuel consumption per kilometer of the track is the lowest.
- 🔧 Timely replacement of candles and cleaning of the carburetor can reduce the consumption of the mixture to 10-15% relative to factory performance.
To calculate the necessary fuel reserve for fishing or cruising, you should always lay a reserve of 20-30%. Fuel tank The standard equipment usually accommodates 24 liters, which is enough for about 3-4 hours of active running. The use of external tanks of larger capacity significantly increases autonomy.
Use only fresh fuel mixture. ethanol gasoline or long shelf life (more than 2 weeks) leads to the dissection of the mixture and the formation of resins, which is harmful to the membranes of the Mikatsu carburetor.
Rules of running: first start and first tanks
The procedure of running is the foundation of a long life for your child. boat-engineNeglecting this step in 90% of cases leads to a reduction in the life of the piston group. Mikatsu 20 It takes about 10 hours of operation or 3-4 fuel tanks to produce, and it's the time when the rings are rubbed against the cylinders and bearings.
The first 10 minutes of work should be carried out exclusively idling, this is necessary to warm up all the nodes and check the circulation of the coolant. After warming up, you can switch to variable load modes, but not exceeding 50% of the maximum power (about 2500-3000 rpm).
☑️ Checklist of successful break-in
During the first two hours of the motor cycle, it is recommended to change the operating modes often: give gas, then discharge, add again smoothly. Monotonous operation at one turn during the break-in is undesirable. After the first 10 hours are produced, you need to replace the workflow. transmission oil, since it may contain metal shavings from the grinding of gears.
⚠️ Warning: Never keep the engine running at full throttle (100% throttle) during the first 10 hours of operation, guaranteed to overheat and bully the piston group, which is not a guarantee.
Maintenance and typical faults
Regular maintenance avoids most problems: main enemy two-stroke Periodically, you need to check the condition of the spark plug: it must have brick-brown soak, black soak indicates a re-enriched mixture, white indicates a poor one.
Lubricant gearbox It requires a replacement once a season or every 100 motor hours, the oil must be transparent; if it has become milky, then the seals are broken and water has been put into the gearbox, and this requires immediate intervention and seal replacement.
Typical faults faced by owners:
- 🔥 Start problems: often lurk in old fuel, contaminated carburetor jelly or candle gap disruption.
- 💨 Power loss: It may be caused by overgrown datadude algae, screw damage or clogging of the fuel filter.
- 🔊 Extraneous noise: indicates wear of bearings or the entry of a foreign object into the screw.
It is useful to use for diagnosis of many problems compressometerThe normal compression for this engine should be within 9-11 atmospheres, and a compression drop below 7 atmospheres indicates the need for repair of the piston group.
Rotor selection and impact on speed
The propeller is a propeller that turns the power of the engine into motion. Mikatsu 20 The standard is a propeller with a pitch of 9-10 inches and a diameter of about 9.25 inches. However, depending on the type of boat and load, the step may need to be changed to reach optimal revs (5000-5500 rpm at full gas).
If the motor is not turning at maximum speed ("not spinning"), the propeller is too heavy (big stride) or the boat is overloaded, in which case the speed will be low and the fuel consumption is high. Conversely, if the motor is overtwisting (it produces more than 6000 rpm), the propeller is too light, which can lead to engine operation outside the optimal power range and potential damage.
| Type of screw | Step (inches) | Materials | Recommended application |
|---|---|---|---|
| Standard. | 9.25 x 10 | aluminum | Inflatable boats, 1-2 people |
| Freight. | 9.25 x 8 | aluminum | Heavy boats, full load, trolling |
| Speed. | 9.25 x 11 | Nerzh. | Light boats, maximum speed |
| Universal. | 9.25 x 9.5 | aluminum | Mixed operating mode |
When choosing a screw, you also need to look at the material. Aluminum screws are cheaper and when hitting an underwater obstacle, they bend, saving the daydude from breaking. Steel screws are stronger and more efficient, but when hit, they can transfer energy to the shaft, damaging it. transmission.
Comparison with competitors and final conclusions
In its price segment Mikatsu 20 It competes with brands like Hidea, Sea-Pro and the more expensive Yamaha and Tohatsu, and the main advantage is the price and availability of parts, and it is structurally very close to the Yamaha 20C, making it easier to find compatible parts, but the quality of casting and assembly may be inferior to the Japanese originals.
Four-stroke analogues of the same power will be quieter, more economical and more environmentally friendly, but they are much heavier (about 55-60 kg) and more expensive to buy and repair. two-stroke It remains the preferred choice.
Mikatsu 20 is the perfect balance of price and thrust for light and medium-sized boats, if you’re willing to put up with making the mix and a little more noise for the sake of budget savings.
So to sum up, this motor requires a careful attitude to fuel and regular lubrication, and with simple rules of operation, it can run hundreds of hours of motorcycling, bringing joy from the water, not a racing car, but a reliable helper for the soul and fishing.
What is the best gasoline for Mikatsu 20?
It is recommended to use AI-92 or AI-95 gasoline from proven gas stations. The main thing is freshness of fuel. Using gasoline with an octane number below 92 can lead to detonation and overheating, and old gasoline (over a month) will inevitably coke the carburetor.
What kind of oil to mix with gasoline?
For two-stroke water-cooled motors such as the Mikatsu 20, special oils labeled TC-W3 must be used. The mixing ratio is usually 1:50 (20 ml of oil per 1 liter of gasoline) for the break-in motor and 1:40 (25 ml) during break-in.
Why does the engine stop on idle?
The most common causes: clogging of the idle jeeler of the carburetor, sucking excess air through the gasket of the intake manifold or improper adjustment of the screw quality of the mixture.
Can the motor be transported horizontally on a boat?
It is strongly recommended not to put the motor on the side without draining the oil from the gearbox. Oil can enter the cylinder through the exhaust windows, which will lead to a hydraulic shock at start. Transport should be strictly vertical or with a slight tilt to the lower unit, but not on the side.