marine engine digest logo


Suzuki 150 hp & Suzuki 175 hp four stroke outboards


Suzuki outboards latest creation is a pair of four-strokes rated 150 and 175 horsepower. Essentially identical twins, the two horsepower ratings share the exact same powerhead. More on why that's such an important detail later on in the story.

What's particularly compelling about the new Suzuki brothers is their impressively light weight, which tips the scales at a mere 465 pounds. Just as impressive is how many cubic inches have been stuffed into such a small package. Bore and stroke calculate to 175 cubic inches worth of displacement, or one cubic inch per horsepower (on the DF 175).

Any marine engine aficionado worth the 30-weight oil coursing through his veins will advise that whenever on a quest to build performance there is absolutely no substitute for cubic inches. That's because the bigger the swing of the crank the more powerfully it performs at lower rpm. Besides impressive displacement the Suzuki twins also own bragging rights to digital fuel injection, a set of overhead cams (DOHC), four valves per cylinder and Variable Valve Timing (VVT). These components work in perfect harmony to lend the mid size four-strokes razor sharp throttle response and the kind of fuel economy you can live with.

In a moment you're going to grasp the notion that Suzuki engineers are obsessed with max torque. Case in point. The lower unit features a eyebrow raising 2.50 to one gear set. Why is as simple as the sea is salt. The lower a gear ratio, the more torque available at the propeller shaft.

Then, in order to better transform latent torque into rapid forward motion, the big gears spin a large diameter, maximum pitch, three-bladed, stainless steel propeller. Greater than normal blade area more efficiently grabs ands holds the water column that propels the boat forward. Acceleration is so rapid it sends a pleasurable shiver reverberating up and down the spine.

Remember earlier in the story when we mentioned how the two brothers are founded upon the same reciprocating mass? The difference in horsepower ratings is as simple as ignition and fuel flow tuning. The 175 revs to higher rpm in order to build more power. From low end thru midrange rpm cubic inches, big gears and oversized propeller very nearly equalize performance between the two motors. Naturally the higher horsepower motor boosts top speed and lends quicker acceleration.