Introduction: why Tohatsu MFS18 Is it popular with boaters?
outboard motor Tohatsu MFS18 The 18 hp model has been one of the most popular in its class for many years, and its Japanese quality, affordable price and unpretentious maintenance make it a favorite among owners of PVC boats and aluminum vessels up to 4.5 meters long. But is it as good in practice as it is written in the brochures?
In this article, we collected real feedback from owners, analyzed the specifications and identified the strengths / weaknesses of the engine. Tohatsu 18 hp. In 2026, what are the problems that you're going to have in operation and how to avoid them, and then compare it to the next big competition. Yamaha F15/20, Mercury F20 and Suzuki DF20.
We'll pay special attention. fuel consumption in different modes This is often the deciding factor when choosing a fishing motor or a long water trip.
Technical specifications Tohatsu MFS18What is hidden in the specifications?
On paper, the engine looks perfect: four-stroke engine, electronic ignition, system Oil Alert It's a way to protect against oil starvation, but let's go through the key parameters in more detail.
- 🔹 Type of engine: four-stroke, 2-cylinder (SOHC) with an upper camshaft. This guarantees quiet operation, but requires quality oil.
- 🔹 Volume.: 346 cm3 is the standard for 15-20 hp engines, but competitors (e.g., the engine is not the same as the engine). Mercury F20) 10-15% more volume.
- 🔹 Transmission: front/reverse with mechanical switching, owners mark the tight switching handle on new engines.
- 🔹 Weight.: 47 kg is one of the lightest in the class, which is a plus for transportation, but a minus for wave stability.
Pay attention. petrol-recommended: the manufacturer specifies the AI-92, but many owners after 2-3 seasons of operation switch the engine to the AI-95. knock-resistance When using the 92nd at high speeds, characteristic "rings" in the cylinders may appear.
| Parameter | Tohatsu MFS18 | Yamaha F20 | Mercury F20 |
|---|---|---|---|
| Power, HP. | 18 | 20 | 20 |
| Volume, cm3 | 346 | 327 | 351 |
| Weight, kg | 47 | 52 | 51 |
| Max. RPM, RPM | 5500-6000 | 5000-5500 | 5300-5800 |
| Recommended oil | 10W-30/10W-40 | FC-W 10W-30 | TC-W3 |
⚠️ Attention.Motors Tohatsu 2018-2020 issues had problems with cooling-off - impellers wore out for 1-2 seasons. Since 2021, the manufacturer has replaced the material with a more wear-resistant one, but when buying a used engine, be sure to check the pump condition!
real owner reviews: pros and cons after 3+ years of operation
We have reviewed over 150 reviews on the forums (including: PVC boat.ru, FishHunt and Drive2) and highlighted the key trends. Here's what the owners say:
✅ The Pros That Mark All
- 🛢️ Economy: fuel consumption at cruising speed (20-25 km / h) - 3.5-4.5 l / h At minimum gas (trolling) - up to 1.8 l / h.
- 🔧 Reliability: With proper maintenance, the engine nurses 5-7 seasons without major repairs.
- 🎵 Silence.: at idle turns almost not audible (48 dB), which is appreciated when hunting fishing.
- 💰 Price/qualityThe new engine is 15-20% cheaper than its counterparts Yamaha or Mercury.
❌ Cons that the sellers are silent about
- 🔥 Overheating: at air temperature above +30 ° C and long operation at high speeds, the engine can go into defense.
thermostat with lower operating temperature. - ⚙️ Weak starter: manual starter often weds after 2-3 seasons. Owners recommend to put the starter immediately from the Mercury 20 hp - he's perfect.
- 🌊 Low-speed vibrations: at speeds below 10 km/h, the engine is shaking. This is a feature of the 2-cylinder design.
- 🛑 Problems with running: the first 10 motor watches require strict compliance with the regime (not higher than 3/4 of the gas), otherwise increased wear of the piston is possible.
Interesting fact: among the owners Tohatsu 18bhp There are some who have driven it for over 1,500 hours without repair, but only if you have:
Use of oil Tohatsu 10W-40 or Yamalube 4M>
Replace oil every 50 hours (at least!)
Washing the cooling system after each trip in salt water
Storage of the motor in a vertical position (45° angle)
Anode check every 20 hours
-->
Comparison with competitors: Tohatsu vs Yamaha vs Mercury
To see if we should overpay for the brand, we compared it. Tohatsu 18 hp with the closest analogues, the benchmarks were five: price, reliability, efficiency, service and additional options.
The main conclusion: Tohatsu lose out to competitors comfort (no power, tight gas handle), but wins in cost and ease of repairFor example, the cost of major repairs Tohatsu 1.5-2 times lower than the Yamaha F20.
| Criteria | Tohatsu MFS18 | Yamaha F20 | Mercury F20 |
|---|---|---|---|
| The price is new, rub. | ~280 000 | ~350 000 | ~370 000 |
| Fuel consumption, l/h (cruiser) | 3,5-4,5 | 4,0-5,0 | 4,2-5,2 |
| Resource to overhaul, motor clock | 1200-1500 | 1500-2000 | 1400-1800 |
| Availability of service centers | Average | Good. | Excellent. |
| Additional options | Electric starter (optional) | Hydropower, electric starter | Electrical starter, system EFI |
If it matters comfort - Take it. YamahaI need it. reliability and simplicity — MercuryAnd if priority is -- price/quality ratiothen Tohatsu MFS18 out of competition.
The Tohatsu MFS18 is the best choice for those looking for an inexpensive but reliable motor for seasonal use (fishing, cruising). Yamaha or Mercury.
Tuning and modernization: what can be improved in the Tohatsu 18bhp?
Even the perfect motor can be made better. Tohatsu MFS18 The following modifications are often carried out:
- Installation of the screw with another stepThe standard propeller (9.25×11) is suitable for most boats, but for heavy aluminum vessels it is better to install a propeller.
9,25×9"- it'll increase traction down. - Replacement of pump by SierraThe original pump serves 2-3 seasons, and Sierra 18-3206 - up to 5 years.
- Installation of an external fuel filterThis protects the carburetor from debris, especially if you're refueling at unknown gas stations.
- Modernization of the ignition systemReplacement of standard candles with NGK BPR6ES improves the start in cold weather.
Careful with tuning associated with increasing power! For example, cylinder swelling or replacing pistons can lead to:
Consequences of improper tuning
🔥 Overheating due to thermal imbalance
💥 Increased wear of the crankshaft and rods
🚫 Loss of warranty (if the motor is warranty)
🛑 The risk of detonation when using AI-92 gasoline
If you want to increase power legally, consider installing it. turboquite from Tohatsu It adds 2-3 hp, but it requires refrigeration.
Typical malfunctions and ways to eliminate them
Even the most reliable engine breaks down. TOP-5 breakdown Tohatsu MFS18 and how they are repaired:
- 🔧 It doesn't start on cold.Cause: clogged carburetor or faulty candles. Solution: washing the carburetor, replacing candles with one. NGK BPR6ES.
- 💦 OverheatingCause: malfunctioning pump or thermostat. Solution: replacement pump (P)Sierra 18-3206) and thermostat check.
- 🔊 Engine knockCause: wear on piston or rod liners, solution: compression diagnostics, overhaul if necessary.
- 🛢️ Increased oil consumptionCause: wear and tear of the oil rings. Solution: change the rings or the capital.
- ⚡ Ignition skipsCause: breaking high-voltage wires or coils, solution: replacing wires and testing the coil with a tester.
The most common problem is carburettor contaminationIt's because of the use of poor quality gasoline, so that you don't break down.
Add a 50 micron filter mesh to the fuel tank, change it every 10 hours, and it will prevent debris from entering the carburetor and prolong the life of the engine.
⚠️ Attention.: If the engine has stalled and won't start, DO NOT pull the starter handle more than 5 times in a row! This can cause the starter cable to break. First check for spark and fuel supply.
Where to buy and how much it costs: new vs b / y engines
The price of a new one Tohatsu MFS18 in 2026, the range of 275,000 to 310,000 rubles Electric starter motors are 20 to 25 percent more expensive. Where do you buy them?
- 🏪 Official dealers3 years warranty, but the price is 10-15% higher. Tohatsu Center Moscow, BoatMotor.
- 🌍 Online shopping: cheaper, but risk running into "gray" imports. Kater.ru, Lodka-PVH.ru.
- 🔄 B/w market: the engine 2020-2022 can be found for 180 000-220 000 rubles. be sure to check the compression and pump condition!
When buying a used motor, pay attention to:
- Compression in cylinders (normal: 10-12 atm).
- Anode condition (severe corrosion is a sign of poor care).
- The lightness of the spinning of the crankshaft (there should be no jamming).
- Availability of documentation and service book.
Average cost of capital repairs Tohatsu MFS18 — 40,000-60,000 rubles. (replacement of piston, rings, bearings) It's 2-3 times cheaper than the competition!
FAQ: Answers to Frequent Questions about Tohatsu 18bhp
❓ Which screw is better to put on Tohatsu 18 hp for an aluminum boat 3.6 m?
For an aluminum boat with a length of 3.6 m, the optimal propeller 3-blade 9.25×11" If the boat is hard to glid, try the screw. 9,25×9" (a smaller step will give more thrust at the bottom.) For speed, you can put 9,25×13"But it'll increase fuel consumption.
❓ Can I use 92 petrol instead of 95?
The manufacturer recommends the AI-92, but in practice, many owners switch to the AI-95 after running, which reduces the risk of detonation at high speeds. If you pour the 92, avoid long-term operation on maximum gas and monitor the engine temperature.
❓ How much oil do I pour in Tohatsu 18 hp?
The volume of oil in the engine. 1.1 litresUse semi-synthetics. 10W-30 or 10W-40 classified FC-W or 4TThe first replacement is after running (10 motor hours), then every 50 motor hours or once a season.
❓ What is the 18 hp Tohatsu resource when used correctly?
Subject to the maintenance regulations (replacement of oil, filters, anode), the engine passes 1,200-1,500 motor-hours There are cases where the engines have worked 2,000+ hours, but this requires perfect operating conditions and regular maintenance.
❓ Can I install an electric starter on Tohatsu 18 hp on my own?
Yes, but you will need to buy a set of electric starter from Tohatsu (article) MFS18-ES-KIT) and battery 12B. The installation takes 2-3 hours, but if you do not have experience, it is better to contact the service. The average cost of the kit is 18,000-22 000 rubles.