This posting is the result of a yearlong test and of Yamaha Motor's F6 small outboard motor. I personally unpacked this 6-hp small outboard motor from its shipping crate and prepped it. That meant adding engine oil to the empty crankcase (drained bone dry for shipping) and also making sure there was plenty of lubricant in the lower unit.
The motor draws fuel from either an integral tank on the top of the engine, or from an external fuel tank and hose. You need to know a three-position petcock hides under the front of the engine. Flip it to choose: Off (no fuel), or either the integral or external tank. I used the on engine tank a fuel reserve.
What attracted me most to this engine was its light weight. At a mere 60 pounds, it weighs 23 pounds less than the previous F6. So naturally it follows the new Yamaha F6 is significantly easier to wrangle onto and off of a dingy transom. Compared to a generic 9.9 horsepower engine the F6 weighs about 30 pounds less. Compared to a generic 6-horse it still weighs less. Yamaha engineers saved weight by founding this small outboard on a single-cylinder power head. The previous F6 had two-cylinders. I was pleased to see how smooth it runs thanks to a balanced crankshaft.
I mentioned portability as an important issue. Notice the carrying handle on the back of the engine. That made it very easy to haul from the car to the dock. Once mounted on the transom, the motor tilts up out of the water with just one hand. My friend, Howard is a veteran who lost his right arm in a rocket attack. He tells me that his next motor will be a Yamaha F6. Shifting from neutral to forward or reverse is via a lever mounted on the side of the engine.
Yamaha F6's significant weight savings comes at a price. The engine is noticeably louder than other four-strokes. Part of that is due to the exhaust flow that exits above the propeller. In other words, this is not a thru-the-prop-hub exhaust which is undeniably quieter. It's not loud, it's just that it's louder than an outboard with thru the hub exhaust.
The Yamaha F6 power head uses a wet sump (0.63 quart) pressurized oil system. Some small outboards splash lubricate. Starting the small outboard was easy, just one pull on the rope. That's because of the CDI ignition replete with Auto Timing Control and an automatic decompression device. There's a dual fuel filter system with an in-tank water trap so ethanol-laced fuel (up to 10% by volume) should be no problem. but to make sure I'll be using an external tank with a fuel/water separator plumbed between the small outboard and the fuel tank.
I liked the way the outboard can be stored in any one of three different horizontal positions, all of which are resist oil trickling out of the motor. Another long term storage feature is the auxiliary primer bulb (under the cowling), which primes the fuel system after lay-up. Another pleasant surprise is the 180-degree steering that made maneuvering in tight spaces much easier.