Yamaha 50hp (2-Stroke) vs Mercury 45hp (Inline-4)

Yamaha

50hp (2-Stroke)

2000 · 50 HP · 2-Stroke
VS
Mercury

45hp (Inline-4)

1975 · 45 HP · 2-Stroke
Spec Yamaha 50hp (2-Stroke) Mercury 45hp (Inline-4)
Power & Performance
Horsepower 50 HP 45 HP
Displacement 698 cc 720 cc ←
Configuration 3 Cyl / Inline 4 Cyl / Inline
Weights & Dimensions
Dry Weight 75 kg (165 lbs) 72 kg (159 lbs) ←
Mechanical & Electrical
Gear Ratio 1.85 2.0
Alternator 144 W ← 113 W
Fuel Delivery Carbureted Carbureted
Maintenance
Spark Plug NGK BR8HS-10 NGK BUHW (Surface Gap)
Engine Oil Yamalube 2-M TC-W3 2-Stroke

Technical Comparison Analysis

Power & Displacement

Comparing the Yamaha 50hp (2-Stroke) and Mercury 45hp (Inline-4) shows a displacement difference of 22cc. The Mercury features a larger 720cc block, which typically provides superior low-end torque and better hole-shot performance when pushing heavy loads or reaching planning speeds.

Weight & Rigging

In terms of transom weight, the Mercury is the lighter option at 72kg, offering a weight saving of 3kg over its competitor. This weight reduction is critical for smaller hulls or boats with limited transom capacity where every kilogram affects the center of gravity and drainage efficiency.

Electrical & Features

For boats equipped with modern electronics, sonar, and shallow-water anchors, the Yamaha offers the best charging performance with a 144W alternator. Choosing the right power-to-weight profile between these two 2-stroke engines depends heavily on your specific boat's displacement and daily power requirements.