Mercury 40hp (Inline-4) vs Johnson 40hp (2-Stroke)
40hp (Inline-4)
40hp (2-Stroke)
| Spec | Mercury 40hp (Inline-4) | Johnson 40hp (2-Stroke) |
|---|---|---|
| Power & Performance | ||
| Horsepower | 40 HP | 40 HP |
| Displacement | 720 cc | 737 cc ← |
| Configuration | 4 Cyl / Inline | 2 Cyl / Inline |
| Weights & Dimensions | ||
| Dry Weight | 72 kg (159 lbs) | 64 kg (141 lbs) ← |
| Mechanical & Electrical | ||
| Gear Ratio | 2.0 | 2.42 |
| Alternator | 113 W | 144 W ← |
| Fuel Delivery | Carbureted | Carbureted |
| Maintenance | ||
| Spark Plug | NGK BUHW (Surface Gap) | Champion QL77JC4 |
| Engine Oil | TC-W3 2-Stroke | TC-W3 2-Stroke |
Technical Comparison Analysis
Power & Displacement
Comparing the Mercury 40hp (Inline-4) and Johnson 40hp (2-Stroke) shows a displacement difference of 17cc. The Johnson features a larger 737cc 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 64kg, offering a weight saving of 8kg 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 Johnson 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.