Stainless Steel Propellers for 4–20 HP Tohatsu Outboard Boat Motor

Selecting the perfect propeller for small outboards can feel like threading a needle: too little thrust and your boat struggles, too much pitch and it labors off the mark. Our marine-grade stainless steel propellers fit Tohatsu models from 4 HP up to 20 HP—ideal for everything from inflatable tenders to nimble fishing skiffs. We don’t pretend to be an “official” Yamaha, Mercury, Suzuki, Volvo, or Honda supplier; we simply engineer props that bolt on and deliver dependable performance.

4–6 HP Models (12-Spline Gearcase)

These low-horsepower propellers thrive on lightweight hulls and inflatable boats. Their three-blade design balances thrust and efficiency, helping you plane quickly and maintain steady idle speeds for fishing or trolling.

Applications: MFS4/5S/6S (4-stroke), M5B (2-stroke)
Gearcase: 12-spline tooth

Insight: At this horsepower, blade stiffness matters. The 7.8″ diameter with an 8″ pitch provides just enough bite to get on plane in seconds—crucial when you’re loaded with gear.

8–9.9 HP Four-Stroke (12-Spline Gearcase)

A step up in power demands a slightly larger propeller. These three-blade models suit small runabouts and deck boats, offering crisp acceleration without sacrificing top-end control.

Applications: 8 HP & 9.9 HP four-stroke (Tohatsu/Nissan)
Gearcase: 12-spline tooth

Tip: The 8.5″×9″ combination boosts low-speed torque, helping you plane faster when carrying a passenger or cooler full of bait.

9.9–20 HP Range (2½″ & 14-Spline Gearcases)

Covering classic two-stroke 9.9 HPs through modern 20 HP four-strokes, this line delivers versatility. Whether you’re towing a skier or cruising solo, there’s a pitch to match your load and speed goals.

Applications:

• 9.9 HP two-stroke (1984 & newer)

• 9.9 HP four-stroke (2000–2003)

• 12 HP (1985–1988)

• 15 HP two-stroke (1985 & newer)

• 15 HP four-stroke (2000 & newer)

• 18 HP four-stroke (1985 & newer; 2001–2008)

• 20 HP four-stroke (2007 & newer)

• MFS9.9/15/18/20; MSF9.9/15/18/20

Gearcase: 2½″ housing, 14-spline tooth

Blade Counts, Pitch & Performance

• Three-Blade Classics: Light steering feel and quick plane-up—ideal for solo runs, light loads, and general cruising.

• Pitch Ranges:

  • 8″–9″: Maximizes low-end thrust for towing tubes or heavy tackle.

  • 10″: Strikes a harmony between acceleration and top speed.

  • 11″–12″: Best for light-load or solo runs when you want peak velocity.

Mixing blade count with diameter and pitch lets you fine-tune how your boat responds. A higher-pitch prop on a solo outing yields extra speed; a lower-pitch, four-blade option offers stability and grunt when you’re loaded up.

Real-World Advice

“Swapping a 9.25″×9″ three-blade for a 9.25″×10″ model on my 15 HP four-stroke cut planing time by nearly a second—plus I still hit 20 MPH with two aboard.”
—Inshore guide, 12 years on the water

1. Sea-Trial Different Pitches. Specs only tell half the story—real-world testing reveals your ideal match.

2. Check Spline Engagement. A tight spline fit prevents vibration and premature wear.

3. Match Prop to Mission. If you tow gear or fish with friends, lean toward lower pitch or add a blade for extra bite.

Installation & Care Tips

• Proper Torque: Follow manufacturer torque specs when tightening the prop nut to avoid wobble or hub damage.

• Freshwater Flush: Rinse after each trip to remove salt and grit.

• Routine Inspections: Look for nicks or bends—small dings can cause cavitation and reduce lifespan.

By matching blade count, diameter, and pitch to your boat’s weight and purpose, these stainless steel propellers will unlock smoother acceleration, tighter handling, and efficient cruising—turning every outing into a memorable voyage. Explore our selection and experience the difference today!