Description
Mercury Outboard Motors 2020 3.5 HP 3.5MH Motor
Product Overview
The Mercury 2020 3.5MH is the epitome of compact, portable power, delivering reliable performance for small boats and lightweight craft. As a 3.5 horsepower, 2-stroke outboard, this motor is engineered for simplicity, ease of use, and effortless portability—weighing in at a remarkably light 24 lbs (10.9 kg). It’s the perfect companion for inflatable dinghies, car-topper boats, jon boats, and canoes where getting on the water quickly and without hassle is the top priority.
Designed with the casual boater in mind, this motor features a single-cylinder engine with a manual start system that is famously easy to pull. Its 2-stroke design means no engine oil changes are required, and it can be stored in any position, making it incredibly user-friendly. The 15-inch short shaft is ideal for smaller transoms, and the integrated carrying handle makes transportation a one-person job.
Whether you’re a sailor needing a reliable tender motor, an angler accessing backwaters, or a family enjoying a small lake, the Mercury 3.5MH offers the trusted brand name and dependable power you need in an ultra-lightweight package.
📚 Boating Resources & Guides
Technical Specifications
| Specification Category | Detail |
|---|---|
| Manufacturer Model Code | 3.5MH |
| Year | 2020 |
| Horsepower | 3.5 HP |
| Shaft Length | 15 inches (Short Shaft) |
| Starting System | Manual Pull Start |
| Weight | 24 lbs / 10.9 kg |
| Cylinders | 1 |
| Engine Type | 2-Stroke |
| Fuel System | Carbureted |
| Fuel Tank | Integral 0.3 US gal / 1.14 L |
| Oil Mix Ratio | 50:1 (Premium 2-Cycle Oil) |
| Gear Shift | Forward, Neutral |
| Steering | Friction Tiller |
| Trim | Manual |
🖼️ IMAGE: [mercury-3.5mh-outboard-side-profile.jpg]
Alt-text: Side profile view of the Mercury 3.5MH outboard motor, showing its compact design and integrated fuel tank.
What’s Included (Typical)
| Included | Not Included / Required Separately |
|---|---|
| ✓ Complete Outboard Motor | ✗ Propeller (Shear pin may be installed) |
| ✓ Integral Fuel Tank | ✗ Fuel Mixing Container |
| ✓ Tiller Handle & Grip | ✗ Fuel Line (Not needed with integral tank) |
| ✓ Mounting Clamps | �* 2-Cycle Outboard Oil |
🛠️ Recommended Accessories
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Security: Outboard Motor Locking Cable
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Transport: Outboard Motor Carry Bag
Comparison Table: Mercury 3.5MH vs. Key Competitors
| Feature | Mercury 3.5MH (2-Stroke) | 4-Stroke 3.5HP Competitor | Electric Trolling Motor |
|---|---|---|---|
| Weight | 24 lbs (Extremely Light) | ~35-41 lbs | 15-20 lbs (without battery) |
| Fuel System | Integrated Tank (Simple) | Often External Tank | Battery Powered |
| Maintenance | Simple (No oil changes) | More Complex (Oil changes) | Very Simple |
| Portability | Excellent (One-handed carry) | Good | Fair (Heavy Battery) |
| Power/Runtime | Long runtime, consistent power | Long runtime, consistent power | Limited by battery capacity |
| Ideal For | Ultimate portability & simplicity | Quieter operation, no fuel mixing | Silent operation, short trips |
Frequently Asked Questions (FAQs)
Q1: Is a 15-inch shaft the right size for my boat?
A: A 15-inch “Short Shaft” is standard for small boats, dinghies, and inflatables with a transom height of 15 to 17 inches. Measure from the top of your transom down to the bottom of the hull (keel) to confirm. If the motor is too long or short, it will not perform efficiently.
Q2: How do I mix the fuel for this 2-stroke motor?
A: This engine requires a 50:1 fuel-to-oil ratio. This means for every gallon of gasoline, you add 2.6 ounces of TC-W3 certified 2-stroke outboard oil. Use a dedicated mixing bottle for accuracy to prevent engine damage.
Q3: What is the fuel consumption like?
A: With its small integrated 0.3-gallon tank and efficient single-cylinder design, the 3.5MH is extremely economical. At full throttle, it will consume roughly 0.3 – 0.5 gallons per hour, giving you about 45-60 minutes of runtime at wide-open throttle, and much longer at slower speeds.
Q4: Can this motor be used in saltwater?
A: Yes, but it requires extra care. Always flush the motor with fresh water after each use in saltwater by running it in a tank or with flushing muffs. Rinse the external casing thoroughly to prevent corrosion.
Q5: What size boat can this 3.5 HP motor push?
A: This motor is ideal for lightweight boats up to 10-12 feet, such as:
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8-10 ft. inflatable dinghies
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10-12 ft. jon boats
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12-14 ft. canoes
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Small sailboats for auxiliary power
Performance will vary based on boat weight, hull design, and load.
Internal Link: Still deciding on power? Read our guide Choosing the Right Portable Outboard Motor.
Pros and Cons
| Pros | Cons |
|---|---|
| Extremely Lightweight: At 24 lbs, it’s easy for anyone to carry and mount. | 2-Stroke Operation: Requires fuel mixing, which some find inconvenient. |
| Super Simple Operation: No battery, no oil changes, and easy pull-start. | Manual Start Only: No electric start option available. |
| Integrated Fuel Tank: Eliminates the need for a separate, bulky fuel tank and line. | Limited Power: Designed for displacement speeds on small, light boats, not for planing. |
| Trusted Brand: Backed by Mercury’s reputation for reliability and quality. | Not as Quiet as 4-Strokes: 2-stroke engines are typically louder and have a distinctive exhaust note. |
| Easy Storage: Can be laid flat without worrying about oil leaks. |
🖼️ IMAGE: [mercury-3.5mh-on-inflatable-dinghy.jpg]
Alt-text: Mercury 3.5MH outboard motor mounted on the transom of a small inflatable dinghy on a calm lake.
Conclusion & Ideal Use Case
The Mercury 2020 3.5MH is the ultimate choice for the boater who values portability and simplicity above all else. It is the workhorse for small watercraft where every pound matters and reliable, fuss-free operation is key.
This motor is perfectly suited for:
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Tenders and Dinghies for larger boats
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Small Fishing Boats and Jon boats
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Canoes and Kayaks with motor mounts
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Car-Topper Boats for spontaneous fishing trips
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Sailors needing a compact auxiliary power source
If your boating style demands a motor that you can grab with one hand, mount in seconds, and trust to start easily, the Mercury 3.5MH delivers unparalleled convenience and dependable power.
🔗 Official Technical Resource
For detailed owner’s manuals, warranty information, and specific maintenance procedures, always refer to the Mercury Marine Owner’s Center for the most accurate and up-to-date information.
