Two stroke outboard motor Nissan Marine 9.8 - one of the most popular units in its power class, combining Japanese build quality, ease of maintenance and an optimal price-performance ratio. This engine became the successor to the legendary models Toatsu (Japanese brand, acquired Nissan in the 2000s), inheriting their reliability and adapting to the modern requirements of fishermen and owners of small boats.
With power 9.8 hp (which corresponds to the maximum category allowed for registration without a license) the motor is ideal for boats up to 4–4.5 meters in length, including popular models like Karych, Kazanka or inflatable PVC boats with a hard bottom. In the article we will analyze unique technical solutions of this engine, including the CDI ignition system, float chamber carburetor and cooling features, which distinguish it favorably from its Chinese counterparts.
Specifications Nissan Marine 9.8 2T: What does a passport hide?
Official manufacturer data often does not reveal all the nuances important for practical operation. Let's take a closer look at the key parameters:
- 🔧 Engine type: 2-stroke, single-cylinder, air-cooled (forced airflow)
- ⚡ Maximum power: 9.8 hp at 5000–5500 rpm (real measurements show stable 9.5 hp during long-term operation)
- ⛽ Fuel consumption: 4.2–4.8 l/h at maximum speed (in economy mode - up to 3 l/h)
- 📏 Working volume: 246 cm³ (comparable with engines Yamaha 9.9 And Mercury 9.9)
- ⚙️ Gear ratioRatio: 2.08:1 (optimal for 9-11 inch pitch propellers)
- 🔋 Ignition system: CDI (contactless, automatic advance)
Deserves special attention float chamber carburetor - it is equipped with a system Prime Start (manual fuel pumping), which simplifies cold starting. Unlike Chinese engines, where the pump often fails, in Nissan Marine 9.8 A metal pump with a membrane made of oil and petrol resistant rubber is used, the service life of which exceeds 500 operating hours.
| Parameter | Meaning | Note |
|---|---|---|
| Motor weight | 38 kg | 2–3 kg lighter than analogues Mercury And Yamaha |
| Max. rpm | 5000–5500 rpm | Excess leads to overheating and wear of the piston group. |
| Recommended oil | TC-W3 (2T) | Synthetics are allowed Motul Outboard Tech 2T |
| Fuel tank capacity | 24 l (external) | Consumption allows you to walk for 5–6 hours without refueling |
| Warranty | 3 years | Subject to service in certified centers |
It is important to consider that the engine is not equipped with feedback from the oxygen sensor (lambda probe), so the quality of the fuel mixture depends entirely on proper preparation. The optimal ratio of oil to gasoline is - 1:50 (20 ml of oil per 1 liter of 92 gasoline). The use of 95 gasoline is not recommended due to the risk of detonation under high loads.
- Nissan Marine
- Yamaha
- Mercury
- Honda
- Other
Advantages and disadvantages: an honest analysis
Like any technically complex unit, Nissan Marine 9.8 2T has strengths and weaknesses. Let's consider them based on owner reviews and expert tests:
Pros:
- ✅ Ignition reliability: The CDI system requires virtually no maintenance for 5-7 years.
- ✅ Easy start: thanks Prime Start The engine starts with 1-2 jerks even after winter inactivity.
- ✅ Resource: with proper running-in and maintenance, the mileage before major repairs reaches 2000–2500 engine hours.
- ✅ Spare parts price: parts (piston rings, spark plugs, membranes) are cheaper than Mercury or Yamaha.
Cons:
- ❌ Noisiness: at high speeds the noise level reaches 92 dB (higher than 4-stroke analogues).
- ❌ Vibration: Single cylinder design results in noticeable vibration at the transom.
- ❌ Fuel sensitivity: When using low-quality gasoline, the carburetor jets quickly become clogged.
⚠️ Attention: Owners often complain about crankshaft oil seal leak after 3–4 seasons of operation. The reason is overheating of the motor during prolonged operation at maximum speed. Solution: Check the oil level in the gearbox every 50 hours and avoid overloading.
For comparison, motors Yamaha 9.9 less noisy, but their repair costs 30–40% more. A Mercury 9.9 It has better traction at low speeds, but is more picky about oil quality. Nissan Marine 9.8 takes the middle ground - it is easier to maintain and cheaper to operate.
When buying a used motor, be sure to check the compression (the norm is 8–9 kg/cm²) and the condition of the magneto. These units most often fail when maintenance regulations are not followed.
Run-in and first maintenance: how to extend the life of the engine?
The first 10 operating hours (running-in period) determine the engine life by 60–70%. Many owners ignore the manufacturer's recommendations, which leads to premature wear of the piston group. Here are the key rules:
- Fuel mixture: use ratio
1:40(25 ml of oil per 1 liter of gasoline) instead of the standard1:50. - Revolutions: Do not exceed 3/4 of the maximum (≈4000 rpm).
- Load: Avoid fully loading the boat and towing skiers.
- Cooling: After each ride, flush the cooling system with fresh water (especially when operating in salt water).
After running in it is necessary to carry out first maintenancewhich includes:
Changing the oil in the gearbox (we recommend Yamalube Gear Oil)|
Checking and adjusting the spark plug gap (the norm is 0.7–0.9 mm)|
Cleaning the carburetor and jets from carbon deposits |
Checking the throttle and reverse cable tension|
Sternwood bearing lubrication (use Liqui Moly Marine-Fett)-->
Pay special attention gearbox. It uses gear oil SAE 90, which needs to be changed every 100 hours or once a season. Neglecting this procedure leads to corrosion of the gears and jamming of the shaft.
⚠️ Attention: Never use automotive gear oil in the gearbox! It does not contain additives that protect against water and leads to the formation of an emulsion that destroys bearings.
What happens if you don’t change the oil in the gearbox?
After 200–300 operating hours, the oil loses its viscosity and protective properties, which leads to:
1) Accelerated wear of bevel gears (appearance of metal shavings).
2) Corrosion of the propeller shaft (especially when operating in salt water).
3) The gearbox jams under load, which requires expensive repairs (from 15,000 rubles).
Comparison with competitors: Nissan vs Yamaha vs Mercury
To understand how much Nissan Marine 9.8 compares favorably with analogues, we will conduct a comparative analysis based on key criteria:
| Parameter | Nissan Marine 9.8 | Yamaha 9.9 | Mercury 9.9 |
|---|---|---|---|
| New price, rub. | 180 000–200 000 | 220 000–240 000 | 210 000–230 000 |
| Weight, kg | 38 | 41 | 40 |
| Fuel consumption, l/h | 4,2–4,8 | 3,8–4,5 | 4,0–4,7 |
| Resource to capital, engine hours | 2000–2500 | 2500–3000 | 2200–2800 |
| Features | Easy to repair, cheap spare parts | Quiet running, smooth acceleration | High thrust at low speeds |
Main advantage Nissan Marine 9.8 — low cost of ownership. For example, a set of piston rings for it costs ~3,500 rubles, while for Yamaha 9.9 — from 6,000 rub. In addition, Japanese service centers often refuse to repair engines of other brands, and with Nissan Almost all workshops are open.
On the other hand, Mercury 9.9 better suited for heavy boats (weight up to 600 kg) thanks to a more powerful gearbox, and Yamaha wins in comfort - vibrations on the tiller are practically absent.
Nissan Marine 9.8 is the optimal choice for those who value the balance of price, reliability and maintainability. It loses to its competitors in comfort, but wins in efficiency and ease of maintenance.
Tuning and modernization: what can be improved?
Despite the balanced characteristics, many owners strive to increase the power or reliability of the engine. Let's consider proven tuning options:
- 🔥 Installing a sports carburetor: for example, Mikuni TM24 increases power by 10–15%, but requires reconfiguring the ignition system.
- 🌀 Replacing the propeller: 10" pitch prop (instead of standard 9") improves low rpm traction.
- ⚡ Ignition upgrade: installation contactless magneto (for example, from Sierra) eliminates cold start problems.
- 🛡️ Corrosion protection: deadwood treatment with anti-corrosion compound CRC Marine Grease extends service life by 30–40%.
However, not all modifications are safe. For example, cylinder boring to increase the volume leads to a decrease in resource and the risk of overheating. It is also not recommended to install direct exhaust - this upsets the back pressure balance and can lead to breakage of the piston rings.
⚠️ Attention: Installation of non-certified parts (for example, Chinese pistons) will void the warranty and may lead to engine jam. All modifications must be approved by the service center.
If you need extra power, consider purchasing Nissan Marine 15 — it has the same cylinder block, but with a modified piston group and carburetor.
Typical faults and solutions
Even the most reliable engine requires attention. Here is a list of the most common problems and their solutions:
| Malfunction | Reason | Solution |
|---|---|---|
| The engine won't start | Clogged carburetor, faulty spark plug | Clean the jets, replace the spark plug (NGK BPR6ES) |
| Overheating | Clogged water channels, low oil level | Flush the cooling system, add oil to the gearbox |
| Vibration at idle | Crankshaft bearing wear or propeller imbalance | Replace bearing or balance screw |
| Power Loss | Worn piston rings, carbon deposits on valves | Disassemble the cylinder, clean off carbon deposits, replace the rings |
One of the most insidious breakdowns - throttle cable break. It occurs due to corrosion of the inner braid of the cable. To avoid this, lubricate the cable with silicone grease once a season (WD-40 Specialist) and check its progress.
If the motor stalls at high speeds, the cause most often becomes lean mixture due to clogging of the fuel filter or air leaks in the hose. Check the tightness of the connections and replace the filter (part number - Nissan 68300-99901).
Owner reviews: real operating experience
Analysis of reviews on forums (FishHunting, BoatPlace) and in VKontakte groups shows that Nissan Marine 9.8 rated an average of 4.5 out of 5. Here are the key points:
- ⭐ Pros according to reviews:
- 🔹 “In 5 years it has never let me down, even after winter it starts from half a turn” (Alexey, Moscow).
- 🔹 “Fuel consumption is really 4 l/h, as stated” (Igor, St. Petersburg).
- 🔹 “Spare parts are always available, repairs are inexpensive” (Dmitry, Novosibirsk).
- ⭐ Cons according to reviews:
- 🔸 “It’s a little noisy at maximum speed, but you get used to it” (Sergey, Yekaterinburg).
- 🔸 “Vibration is transmitted to the tiller, hands get tired during long work” (Anton, Krasnoyarsk).
- 🔸 “After 3 years, the pan gasket leaked - I had to change it” (Oleg, Kazan).
Interestingly, most complaints are not related to design flaws, but to improper use. For example, many people complain about bad starting in cold weather, but at the same time they admit that they did not drain the fuel before winter storage or used cheap oil.
Among professional fishermen, the motor is valued for predictability: It has no electronic systems that can fail offshore and can be easily repaired in the field.
FAQ: answers to frequently asked questions
Is it possible to use 95 gasoline instead of 92?
No, the manufacturer only recommends AI-92. 95 gasoline has a different additive composition, which can lead to detonation and accelerated wear of the piston group. If there is no choice, it is better to dilute 95 gasoline with 92 gasoline in a 1:1 ratio.
Which propeller is best for a heavy boat?
For boats weighing more than 400 kg, a pitch propeller is recommended 9–10 inches and diameter 230–250 mm. Optimal models:
- 🔹 Michigan Wheel Apollo (aluminium, 10" pitch) - improves traction at low speeds.
- 🔹 Solas Amita (stainless steel, 9" pitch) - increases maximum speed.
How much does a major renovation cost?
The cost of a major overhaul in a certified center is 25,000–35,000 rub., including:
- 🔧 Replacement of the piston group.
- 🔧 Grinding the cylinder (if necessary).
- 🔧 Replacement of seals and bearings.
With self-repair, costs are reduced to 10,000–15,000 rubles. (including the purchase of spare parts).
How to properly preserve a motor for the winter?
The conservation process includes 5 mandatory steps:
- Drain the fuel from the carburetor and tank.
- Start the engine at idle speed to burn off any remaining gasoline.
- Pour 20–30 ml of oil into the cylinder Fuchs Anticorit and turn the crankshaft.
- Remove the propeller, clean the gearbox of old oil and fill with new oil.
- Treat external surfaces with anti-corrosion spray (CRC Marine Corrosion Inhibitor).
Where to buy original spare parts?
Official dealers Nissan Marine in Russia:
- 📍 Moscow: nissan-marine.ru
- 📍 St. Petersburg: spb-boat.ru
- 📍 Regions: spare parts can be ordered through boatparts.ru (delivery within the Russian Federation).
Alternative - online stores eBay or AliExpress, but there is a high risk of running into a fake.