Tohatsu M9.9D2 (2-Stroke) vs Mercury 9.8hp (Blue Stripe)
M9.9D2 (2-Stroke)
9.8hp (Blue Stripe)
| Spec | Tohatsu M9.9D2 (2-Stroke) | Mercury 9.8hp (Blue Stripe) |
|---|---|---|
| Power & Performance | ||
| Horsepower | 9.9 HP | 9.8 HP |
| Displacement | 247 cc ← | 180 cc |
| Configuration | 2 Cyl / Inline | 2 Cyl / Inline |
| Weights & Dimensions | ||
| Dry Weight | 41 kg (90 lbs) | 30 kg (66 lbs) ← |
| Mechanical & Electrical | ||
| Gear Ratio | 1.85:1 | 2.00:1 |
| Alternator | 80 W | 0 W |
| Fuel Delivery | Carbureted | Carbureted |
| Maintenance | ||
| Spark Plug | NGK B7HS-10 | NGK BP7HS |
| Engine Oil | TC-W3 (50:1) | 50:1 Pre-mix |
Technical Comparison Analysis
Power & Displacement
Comparing the Tohatsu M9.9D2 (2-Stroke) and Mercury 9.8hp (Blue Stripe) shows a displacement difference of 67cc. The Tohatsu features a larger 247cc 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 30kg, offering a weight saving of 11kg 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 Tohatsu offers the best charging performance with a 80W 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.