British Seagull Model 102 Century Plus vs Yamaha F4 Portable

British Seagull

Model 102 Century Plus

1970 · 4 HP · 2-Stroke
VS
Yamaha

F4 Portable

2024 · 4 HP · 4-Stroke
Spec British Seagull Model 102 Century Plus Yamaha F4 Portable
Power & Performance
Horsepower 4 HP 4 HP
Displacement 102 cc 139 cc ←
Configuration 1 Cyl / Single 1 Cyl / Inline
Weights & Dimensions
Dry Weight 22 kg (49 lbs) ← 27 kg (60 lbs)
Mechanical & Electrical
Gear Ratio 2.5 2.08:1
Alternator 0 W 0 W
Fuel Delivery Carbureted Carbureted
Maintenance
Spark Plug Champion D16 NGK CR6HSB
Engine Oil SAE 30 (10:1) Yamalube 4-Stroke

Technical Comparison Analysis

Power & Displacement

Comparing the British Seagull Model 102 Century Plus and Yamaha F4 Portable shows a displacement difference of 37cc. The Yamaha features a larger 139cc 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 British Seagull is the lighter option at 22kg, offering a weight saving of 5kg 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 0W 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.