Yamaha has introduced its new F115B and F175A lightweight 4-stroke outboards. The 115B replaces Yamaha’s F115A 4-stroke, and is a versatile choice for a wide range of boats.
The F115B weighs in at 377 pounds, which according to Yamaha is the lightest 115 in its class. Yahama test data reveals a 20% improvement better fuel economy over the 115A in the 3000 to 5000 rpm cruise range and a 10% improvement in acceleration.
Other features include multipoint Electronic Fuel Injection and micro-computer control. The F115B’s all-new powerhead provides increased bore and stroke, which now measures a full 1.8 liters. The outboard’s double-overhead cam (DOHC) 4-cylinder design has larger intake and exhaust valves for easier breathing, more power and better midrange torque.
Complementing the new valves and cylinder head is a new 60mm single-throttle body with Yamaha’s long-intake track system and a new free-flow exhaust manifold. Compression ratio is increased, along with the full-throttle rpm range: 5,300 to 6,300 rpm.
The engine’s high-output alternator cranks out 35 amps at WOT; 28 amps at a low 1000 rpm.
To help fight corrosion, the F115 is protected by Yamaha’s Phaze Five paint system, which involves the electro-deposition of anti-corrosive paint on both the outside and inside passages of the engine block. The outboard also includes Yamaha’s Variable Trolling RPM Switch and can be equipped with Yamaha’s Multifunction Tiller Handle.
Contact information may be found on the Yamaha website.