6 Best Long Shaft Outboards For Pontoon Boats For Cruising

There is nothing quite like the freedom of a slow afternoon on the water, provided your engine is actually pushing you forward rather than sputtering at the dock. Choosing the right outboard for your pontoon isn’t just about raw speed; it’s about matching the right torque and shaft length to your vessel’s unique geometry. Let’s break down the best long-shaft options to ensure your time on the water is spent relaxing, not troubleshooting.

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Why Long Shaft Motors Suit Pontoon Boats

Pontoon boats are essentially floating platforms with a high center of gravity and a unique hull design that sits differently in the water than a traditional V-hull. Because the transom is often set higher to accommodate the deck height, a standard short-shaft motor will frequently suffer from ventilation, where the propeller sucks air and loses its bite.

A long-shaft (typically 20-inch) or extra-long-shaft (25-inch) motor ensures the propeller stays submerged even when you’re carrying a full load of friends or navigating through choppy water. If your prop is constantly breaking the surface, you’re wasting fuel and putting unnecessary strain on your engine’s lower unit. Getting the shaft length right is the single most important step in achieving efficient, consistent propulsion.

Yamaha F70LA: Reliable Mid-Range Power

The Yamaha F70LA is the gold standard for pontoon owners who prioritize longevity over raw, aggressive speed. It’s a 70-horsepower, four-stroke engine that balances weight and power perfectly, making it ideal for standard 20-to-22-foot pontoons that aren’t being used for high-speed towing.

You’ll love this motor if you want a "turn-key" experience where maintenance is predictable and parts are available at every marina in the country. It’s quiet, fuel-efficient, and arguably the most reliable mid-range engine on the market. If you’re looking for a dependable daily driver for cruising, this is the one to buy.

Mercury 60HP Command Thrust for Heavy Loads

If your pontoon is a "party barge" loaded with heavy furniture, a large grill, and a full cooler, the standard 60HP motor might struggle to get you on plane. Enter the Mercury 60HP Command Thrust, which features a larger gearcase and a bigger propeller diameter specifically designed to push heavy displacement hulls.

This motor is essentially a workhorse disguised as a pleasure-cruising engine. By utilizing a larger propeller, it provides significantly more leverage, which translates to better acceleration and control in tight docking situations. If your boat is heavy or you frequently carry a crowd, don’t settle for a standard gearcase; get the Command Thrust.

Honda BF90: Best Fuel Efficiency for Cruises

Honda has a legendary reputation in the automotive world, and their marine engines carry that same DNA of precision engineering. The BF90 is a powerhouse that remains incredibly fuel-efficient, even when you’re pushing a pontoon at cruising speeds for hours on end.

This engine is perfect for the boater who plans to spend entire weekends on the water without wanting to stop for gas every few hours. It’s remarkably quiet at idle, which keeps the atmosphere on your boat peaceful rather than noisy. If your priority is long-range cruising and low noise levels, the BF90 is your best investment.

Suzuki DF115B: High Performance for Pontoons

For those who want to turn their pontoon into a legitimate water sports machine, the Suzuki DF115B is the heavy hitter. With its Lean Burn Control system and high displacement, it delivers impressive torque that makes pulling tubers or water skiers feel effortless.

This is a beefy engine, so you need to ensure your pontoon’s transom is rated for the weight and power output of a 115HP motor. It’s not for the casual cruiser who just wants to drift; it’s for the boater who wants to cover distance quickly and reliably. If you have a larger, triple-toon boat, this engine provides the necessary muscle.

Tohatsu MFS50: Best Lightweight Reliability

Not every pontoon needs 100+ horsepower, especially if you’re cruising small lakes or calm rivers. The Tohatsu MFS50 is a fantastic, lightweight option that keeps the rear of your boat from dragging, which helps with overall trim and stability.

Tohatsu is often the "hidden gem" of the outboard world, offering excellent build quality at a price point that usually undercuts the big three manufacturers. It’s simple, robust, and easy to maintain. If you’re running a smaller pontoon and want a motor that is light on your wallet and your transom, look no further.

Evinrude E-TEC 90: Superior Torque Output

While Evinrude has ceased new production, the E-TEC 90 remains a highly sought-after option on the secondary market for those who understand the benefit of two-stroke torque. It delivers power instantly, which is a massive advantage when trying to maneuver a large, wind-catching pontoon in a busy marina.

The E-TEC’s unique direct-injection technology provides a punchy, responsive feel that four-strokes often lack. If you can find a well-maintained unit, it’s a powerhouse that handles heavy loads with ease. Just be aware that parts and specialized service are becoming more niche compared to the major four-stroke brands.

Key Factors for Choosing Your Shaft Length

Before you buy, measure the distance from the top of your transom to the bottom of the hull. A 20-inch transom generally requires a long-shaft motor, while a 25-inch transom requires an extra-long shaft. Getting this wrong leads to "porpoising" or severe cavitation.

• Load Distribution: A heavier boat sits lower, potentially requiring a longer shaft to maintain depth.
• Water Conditions: If you frequent rougher, open water, a longer shaft ensures the prop stays buried during swells.
• Manufacturer Specs: Always check your pontoon manufacturer’s plate; it will specify the recommended shaft length for your specific model.

Proper Mounting and Transom Height Setup

Mounting an outboard too high or too low is a recipe for poor performance. Ideally, the anti-ventilation plate—the flat fin just above the propeller—should be level with or slightly above the bottom of the pontoon’s center log.

If the motor is mounted too low, you’ll create unnecessary drag and burn more fuel. If it’s too high, the engine will overheat because it can’t pull in enough cooling water, and the prop will cavitate. Use a jack plate if you need to fine-tune your height, as it allows for vertical adjustments to find that "sweet spot" for your specific load.

Maintenance Tips for Reliable Outboard Life

The secret to a long-lived outboard is consistent, boring maintenance. Flush your engine with fresh water after every single trip in saltwater to prevent internal corrosion, and keep your fuel system clean by using a high-quality water-separating fuel filter.

Don’t ignore the gear oil; change it at least once per season to check for water intrusion, which is a tell-tale sign of a failing seal. If you store your boat for the winter, stabilize your fuel and fog the engine to protect the cylinders. Treat your engine well, and it will start on the first turn every time you head to the lake.

Selecting the right long-shaft outboard is a balance of your boat’s weight, your intended use, and your maintenance budget. Whether you opt for the raw torque of a 115HP or the quiet efficiency of a 50HP, the goal is always the same: getting you out on the water with confidence. Choose wisely, keep up with your service intervals, and enjoy the peace of mind that comes with a reliable engine.