Both lighter and more efficient that its worthy predecessor, the new model F115 is based on Yamaha's proven in-line, four-cylinder DOHC, 16-valve, four-stroke outboard that has set the standard for reliability and durability. The redesigned F115 also features a number of tantalizing technologies. Let's begin at the beginning.
The new F115 draws its breath via a new, long-track intake system with a single throttle valve and a resonator. The payoff is as simple as the sea is salt: Improved throttle response. Truth be told, the long track intake technology is nothing new. I first saw it back in the 60's on the venerable Chrysler slant six car engine. (Seems like those engines ran forever.)Incorporating long track intake runners in a 4-stroke outboard more is pure genius.
More insight into what makes this engine tick. F115's combustion chambers were re-contoured in order to increase combustion efficiency. That means Yamaha engineers spent hundreds of hours on the flow bench, tweaking and tuning and die-grinding until they spun straw into gold. Also, the ECM controlled electronic fuel injection system more precisely controls the combustion process, spraying the exact number of fuel droplets needed at the precise moment needed for maximum fuel economy and razor sharp acceleration.
The Yamaha Marine 115 hp 4-stroke outboard motor features:
A Long Intake Manifold (Above-Left)
A 16-Valve-DOHC Block (Above-Right)
There's more. New to the horsepower-rating is knock sensor integrated into the ECM in order to provide protection from engine-killing knocking. An ancillary benefit, is improved combustion efficiency. If the engine knows in real time where the danger zone is, it can bump up horsepower right up against the danger mark. Suffice it to say a knock sensor wrings maximum performance and acceleration out of the Yamaha F115. Oh, yeah, and it boosts fuel economy too.
Know that the cowling was re-designed to improve the flow of air into the engine, benefiting both horsepower and cooling. Venting restrict water intrusion enabling the the outboard to better resist corrosion. Finally, the F115 comes with Yamaha's three-year limited warranty for pleasure use and is three-star certified by the California Air Resources Board (C.A.R.B.) for sale in California.
|Cylinder head||DOHC - 16 Valves|
|Operating Range||5000-6000 rpm|
|Compression Ratio||9.7 to 1|
|Fuel||Minimum 89 Octane|
|Transom Height||20" and 25"|
|Gear ratio||2.15 to 1|