If you have an inflatable dinghy with a keel and a fixed transom, you might want to invest in a gasoline-powered outboard motor.
Unlike electric trolling motors, outboard motors can make your boat go fast. You’ll be able to get your boat on plane, which is always a thrill.
Best outboard motors for SIBs
Here are the most reliable outboards you can buy in 2020:
3.6 HP Outboard Motor Two Stroke Boat Engine
- Cooling: water
- Maximum output: 3.6 HP
- Displacement: 49 cubic centimeter
- Speed: 20km/h (200kg or 440 lbs)
- Fuel tank: 1.3 L
- Operating range: 4,500-5,000r/min
- Idling: 2,700-2,800r/min
- Ignition system: CDI system
- Starting system: Pull start
- Propeller mark: 7-1/4 x 5-A(inch)
- Overall length: 92 cm
- Overall width: 38.5 cm
- Overall height: 22.8 cm
- Transom height: 42 cm (16.5 inch)
- The engine and the propeller gear ratio: 2:1
- Gear ratio: 27/13
- Fuel mixing ratio: 25:1
- Weight: 9.7kg
This Outboard Motor features a 360-degree steering rotation with a lift and tilt feature for operating in shallow water. The exterior and propeller are both made from durable double cast aluminum, which is extremely rust-resistant. It also has a vertical mount engine and a standard CDI ignition system for easy starting.
F2C 3.5 HP Superior Engine Water Cooling System Outboard Motor
- Overall length:102 cm
- Overall width: 45 cm
- Overall height: 30 cm
- Weight:18 kg
- Full throttle operating range: 4,200-5,300 rpm
- Maximum output: 2.5 kw / 3.5HP
- Type: 2-stroke
- Ignition system: CDI system
- Cooling system: Water cooling
- Starting system: Manual
- Starting carburetion system: Choke valve
- Gear positions: Forward-neutral
- Gear ratio:2.08 (27/13)
- Trim and tilt system: Manual tilt
- Recommended fuel: Regular unleaded gasoline
- Engine oil type: Genuine or recommended 2str engine oil
- Spark plug：27.0 nm
- Engine oil drain bolt：20.0 nm
The F2C Outboard Motor has a superior engine cooling system that will prevent the engine from heating up while in use. It also has a lift and tilt feature for easier steering, especially in shallow water. It has a heavy-duty aluminum exterior housing and propeller. This outboard motor runs on regular unleaded gasoline.
Mercury 20 HP Electric Start 4 Stroke Outboard Motor
- Engine Type: 4-stroke
- Features: 4-stroke technology-quiet, environmentally friendly, 40% more fuel efficient than comparable 2-stroke engines, smooth running/exceptional idling
- Exhaust: Thru-prop
- Start: electric Start-up system
- Steering Type: Tiller (2.5-6hp), tiller or remote (8 and higher)
- Gearing: F-N-R, 2.15:1; Model 10181675-F-N-R
- Trim Positions: 5 + shallow-water drive
- Tank Type: External
- Tank Capacity: 6.6gal.
The Mercury Outboard Engine features an ultra-quiet and smoke-free operation. Unlike the first two motors listed above, Mercury Outboard Engine has an electric start-up system. It also features a multi-functioning tiller handle, auto ratchet title, and vibration absorbing wishbone mount.
This outboard motor is the most popular pick for fuel-powered engines. It is powerful, reliable, durable, and portable. It is especially popular for having the ease of maneuver of 2 stroke engines in a 20 HP 4-stroke motor.
Parsun 20 HP Four Stroke Outboard Motor
- Engine type: 4-stroke 2-cylinders, DOHC
- Displacement: 362 cc
- Bore x Stroke mm (inches): 63.0×58.1(2.48×2.29)
- Max output: 20HP / 14.7kw
- Full throttle RPM range: 5000~6000
- Ignition system: CDI
- Starting system: Manual (F20ABMS / F20ABML)
- Starting system: Manual and Electric Start (F20ABWS / F20ABWL)
- Steering system: Tiller control
- Gear shift: Forward-Neutral-Reverse
- Gear ratio: 2.08:1 (27/13)
- Trim and tilt system: 4 positions/Shallow drive
- Max fuel consumption: 6.9 L/h
- Fuel tank capacity: External 24L
- Sump oil capacity: 1.6L
- Gear oil capacity: 300cc
- Dry weight:
F20ABMS – 114Lbs (51.7KG);
F20ABWS – 119Lbs (53.7KG);
F20ABML – 118Lbs (53.7KG);
F20ABWL – 123Lbs (55.7KG)
- Overall width: 16.5 inches / 420 mm
- Recommended transom height: Short Shaft 15-16 inches; Long Shaft 20-21 inches
- Propeller: Aluminum 3-91/4″x11″,
- Alternator output: 12V DC* (optional on manual start model)
- Recommended Oil: 10W-30 or 20W-40
Parsun Four Stroke Outboard Motor has an exterior housing constructed from high-marine aluminum alloy. It is highly resistant to rusting and corrosion. It also has zinc coating on internal water passages to prevent them from rusting. The Parsun Motor also gives available options to fit customers’ preference: electric start or manual start and short or long shaft.
Coleman 2.6HP Manual Start Outboard Motor
- Lightweight (37.5lb)
- 4-stroke Motor
- 31 gallon internal gas tank
- Easy start TCI ignition
- F-n/360 degree steering
- 1 cylinder OHV engine
- CE & EPA Approval
The Coleman Outboard Motor has the smallest power output in this list. There is, however, an available 5 HP for the same engine, but this is the more popular option between the two. This engine is perfect for SIBs. It has 1 cylinder OHV 4-stroke motor, and the entire equipment weighs 37 lbs. The engine operates efficiently and quietly. It also features 360-degree steering, with adjustable steering friction and vibration reduction, perfect for maneuvering through shallow water. It has a marine alloy exterior that is durable and rust-proof.
How strong should your outboard engine be?
Bigger doesn’t always mean better. In choosing the perfect HP for your inflatable boat, there are two factors you need to take in consideration:
Boat Usage and Needs
Boat HP ratings are essential in guiding you on how much power your boat will need. However, you should also take in consideration what you intend to use the boat for. This also includes who, what, and how many/much will you load into your boat during operations.
Maneuvering on rough seas and carrying too many people or gears aboard may affect the performance of your motor. If you use low HP in powering your boat under the conditions stated above, there is a tendency for your motor to do heavy work during operations. Needless to say, having insufficient HP on your boat under the same conditions will not even be enough to power it up in the first place; so, it really is an important factor to consider.
Typically, buyers will opt to buy the least HP needed especially for boats they use for recreation. For example: If you have a boat that is rated for a motor with 50 to 90 HP, people will usually buy a 50 HP outboard motor. Ideally, it will get the job done. However, that 50 HP motor will work harder and will require more fuel; this can considerably shorten your motor’s life span and cost you a lot in refueling, so consider meeting the rating halfway by buying a 70 HP motor.
Another factor to consider is your motor’s fuel efficiency. The amount of fuel that you will need will also depend on the horsepower of your motor. In general, a gasoline engine will burn 0.50 lb per HP and a Diesel engine will burn around 0.40 lb per HP.
You know what this means! That’s right, the higher the HP, the higher the fuel consumption. Fortunately, as stated in the section above, there are instances wherein an engine burns fuel more than what it normally does.
One of those situations is over the performance of an outboard motor because of HP mismatch with usage and luggage. Another is operating your boat in full-throttle; this burns your fuel the fastest. When out in the water, do not leave your throttle wide open; operating with two-thirds to three-thirds throttle will save you lots of fuel.
Note: If you’re having a hard time estimating how much HP you will need, you can use this HP calculator to determine the best motor for you. Simply, fill in the blanks and let it calculate for you.
Outboard Motor Maintenance
Below are some reminders on how to make your outboard engine last a long time:
- Flush out the engine, via its water pump. To flush it out, simply turn on the motor and let its water pump do the rest of the work. You may need to check on the flow of the water pump though to ensure it has no problems.
- Remember to let the engine burn all the remaining fuel before keeping it in storage.
- Regularly inspect the engine for leaks, cracks, and worn out parts.
- Lubricate all the moving parts of your engine such as: carburetor valves, shaft, and etc.
To guide you better, watch this video about Outboard Motor Maintenance.