Johnson 4hp Twin (2-Stroke) vs Yamaha F4 Portable
4hp Twin (2-Stroke)
F4 Portable
| Spec | Johnson 4hp Twin (2-Stroke) | Yamaha F4 Portable |
|---|---|---|
| Power & Performance | ||
| Horsepower | 4 HP | 4 HP |
| Displacement | 87 cc | 139 cc ← |
| Configuration | 2 Cyl / Inline | 1 Cyl / Inline |
| Weights & Dimensions | ||
| Dry Weight | 15 kg (33 lbs) ← | 27 kg (60 lbs) |
| Mechanical & Electrical | ||
| Gear Ratio | 1.65 | 2.08:1 |
| Alternator | 0 W | 0 W |
| Fuel Delivery | Carbureted | Carbureted |
| Maintenance | ||
| Spark Plug | Champion L77JC4 | NGK CR6HSB |
| Engine Oil | TC-W3 2-Stroke | Yamalube 4-Stroke |
Technical Comparison Analysis
Power & Displacement
Comparing the Johnson 4hp Twin (2-Stroke) and Yamaha F4 Portable shows a displacement difference of 52cc. 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 Johnson is the lighter option at 15kg, offering a weight saving of 12kg 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.