Honda BF135 PGM-FI vs Mercury 125hp OptiMax

Honda

BF135 PGM-FI

2015 · 135 HP · 4-Stroke
VS
Mercury

125hp OptiMax

2010 · 125 HP · 2-Stroke
Spec Honda BF135 PGM-FI Mercury 125hp OptiMax
Power & Performance
Horsepower 135 HP 125 HP
Displacement 2354 cc ← 1522 cc
Configuration 4 Cyl / Inline 3 Cyl / Inline
Weights & Dimensions
Dry Weight 217 kg (478 lbs) 170 kg (375 lbs) ←
Mechanical & Electrical
Gear Ratio 2.14:1 2.07:1
Alternator 792 W 864 W ←
Fuel Delivery PGM-FI DFI (Direct Injection)
Maintenance
Spark Plug NGK IZFR6K-11 NGK IZFR6J
Engine Oil Honda 10W-30 Mercury OptiMax/DFI Oil

Technical Comparison Analysis

Power & Displacement

Comparing the Honda BF135 PGM-FI and Mercury 125hp OptiMax shows a displacement difference of 832cc. The Honda features a larger 2354cc 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 170kg, offering a weight saving of 47kg 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 Mercury offers the best charging performance with a 864W alternator. Choosing the right power-to-weight profile between these two 4-stroke engines depends heavily on your specific boat's displacement and daily power requirements.