Mariner 20hp International (Yamaha-built 653) vs Mercury 18hp (2-Stroke)

Mariner

20hp International (Yamaha-built 653)

1990 · 20 HP · 2-Stroke
VS
Mercury

18hp (2-Stroke)

1990 · 18 HP · 2-Stroke
Spec Mariner 20hp International (Yamaha-built 653) Mercury 18hp (2-Stroke)
Power & Performance
Horsepower 20 HP 18 HP
Displacement 395 cc ← 300 cc
Configuration 2 Cyl / Inline 2 Cyl / Inline
Weights & Dimensions
Dry Weight 48 kg (106 lbs) 39 kg (86 lbs) ←
Mechanical & Electrical
Gear Ratio 2.08 2.0
Alternator 126 W ← 60 W
Fuel Delivery Carbureted Carbureted
Maintenance
Spark Plug NGK B7HS NGK B7HS
Engine Oil TC-W3 2-Stroke TC-W3 2-Stroke

Technical Comparison Analysis

Power & Displacement

Comparing the Mariner 20hp International (Yamaha-built 653) and Mercury 18hp (2-Stroke) shows a displacement difference of 95cc. The Mariner features a larger 395cc 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 39kg, offering a weight saving of 9kg 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 Mariner offers the best charging performance with a 126W 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.