Profisher
The older Yamaha 300 hp engines were 8 cyl and the new engine are thermally applied plasma fusion on the cyl walls which is 60% stronger than steel. The same as used in formula 1 car for the past years.
This is what sold me on the 300 hp
Here is the web site info
http://www.yamaha-motor.com/outboard/v6offshore_micro/discover/features
The next generation of Yamaha V6 four strokes.
They're quicker, stronger, smarter and lighter—with class-leading 4.2L displacement that outperforms comparable four strokes on time-to-plane, cruise speed, weight—even fuel economy.* These are just a few of the design advancements that are putting it miles ahead of the competition.
Design Advancement
Benefit
Next-generation engine block features plasma-fused sleeveless cylinder walls, which are 60% stronger than steel, and much lighter
Displacement is increased without enlarging the outer diameter of the cylinder resulting in class-leading, 4.2L displacement and greater durability, power and torque.
Lightest weight in class, featuring an advanced polymer composite lower pan, a completely new cowling, and substantial internal weight savings; all without sacrificing durability
At 562 pounds, the F300 is 242 pounds lighter than the Yamaha V8 F300 it replaces, and 47 pounds lighter than the Yamaha F250 and F225. It’s also up to 73 pounds lighter than competitive 300hp four stroke outboards.
Micro-textured Cylinder Walls, resulting from the plasma-fusion process
Helps retain motor oil on the cylinder walls, greatly reducing friction and substantially increasing fuel economy and power
14% larger intake, 10% larger exhaust valve area, a new Long Track Intake System and Yamaha-exclusive In-BankTM Exhaust
Engine breathes easier, for substantially quicker time-to-plane than competitive 300hp four stroke outboards and up to 19% faster at cruise (4000 rpm)*, with equivalent or better top speed
Variable Camshaft Timing advances and retards the angle of the intake camshaft
Dramatically increases power and throttle response in the low-and mid-rpm ranges, for unbelievable hole shot and acceleration
Saltwater Series II propeller with patent-pending Shift Dampener System (SDS™)
Legendary performance, but with greatly reduced noise and vibration commonly associated with shifting into gear, for smoother, quieter operation
Single 75mm electronically-controlled throttle valve and Precision Multi-point Fuel Injection System
Ensures the precise amount of air and fuel necessary for optimum power and efficiency—up to 17% better long-range fuel economy at 3500 rpm than other 300hp four strokes*
Dual forward- and side-mounted cooling water inlets
Inlets operate independently (as pairs) to keep the engine cool in a variety of applications and conditions, enhancing reliability
Air Intake Labyrinth System
Traps and drains water that enters the cowling during normal operation, before it enters the engine’s intake, for greater reliability
More powerful under-flywheel marine alternator
70 total amps of charging power—29% more than competitive V6 four stroke outboards—helpful for powering a wide array of on-board electronics
