Is the boating world ready for a 350 hp 4-stroke V-8 outboard? When I first heard about this 804-pound heavyweight, I had some serious doubts. But the growing ground swell of comments and observations trickling down the information pipeline in recent weeks has chiseled away at my personal reservations. Many of the larger boatbuilders have already expressed serious interest in the 350, including Grady-White, and one dealer has ordered 160 engines. Availability is expected for July.

Many observers see a single 350 as ideal for boats where a single 300 isn’t quite enough to allow an economical cruising speed, or for replacing triples with just two outboards. There are some pretty strong arguments for this.

First, there is no way to get twin 4/c 175s on a transom without topping the 900-pound mark. Twin Suzukis weigh 930 lbs. A pair of Merc Verados, 1020. Even 2/c DIs would be a little heavier: twin Evinrude E-TECs at 820 lbs, two Merc Optimaxe’s at 862 lbs, and a pair of Yamaha own HPDIs at 936 lbs.

Then there’s the cost of maintenance and repair for two engines instead of just one (or three instead of just two). Initial cost for a single 350 (MSRP is @ $26,245), which would be somewhat less than for twin engines, especially by the time all the installation costs were totaled. Don’t forget, twins take two of almost everything, including binnacles, cables, gauges, and so on.

Those of you who read my recent Power column on Suzuki’s V-6 300 horsepower 4-stroke (January/February, 2007, www.boatdigest.com) are well aware by now that Yamaha’s V-8 is not the first outboard in that configuration. OMC tried it during the 1980s with a 590-pound 2-stroke that delivered 250-300 hp. But that engine was really a case of being in the wrong place at the wrong time. There just weren’t enough transoms out there big enough to handle that much engine. Besides, it had poor low-end acceleration and a serious thirst for gas and outboard oil.

The Yamaha 350 is an all-new 60-degree V-8 with 32 valves (four valves per cylinder) and double overhead cams. It uses variable camshaft timing to optimize the engine’s torque at low and mid-range rpm, along with sequential, multi-point fuel injection. The displacement is 5.3 liters (5330 cc, 325 cu.in.) with a full-throttle operating range of 5000–6000 rpm. It also runs on 89 octane gasoline, has a gear ratio of 1.73:1, plus an alternator output of 40A at 1000 revs and max output of 50A. That’s more than enough for every kind of offshore electronics you might need. It’s available shaft lengths are 25 and 30 inches.
No More Model Years?

As of this point most of the largest outboard makers have dropped the Model Year concept (Bombardier & Suzuki are not yet among these). The idea is to simply introduce new models whenever they are really ready, rather than rush to meet specific model year deadlines. My own observations over the years is that rushing new models to market has led to some real maintenance and repair problems for the consumer. Remember OMC’s seemingly endless difficulties with pressure-back piston rings in the 1970s? It was an excellent concept in terms of engineering, allowing much improved performance without increasing piston displacement. But the company put engines with these rings on the market before the technology was really ready, and had to eat a lot of trashed powerheads under warranty as a result. Once they got it right, it proved to be everything the OMC engineers had expected.

This scenario has been repeated many times over the years, in one form or another, by every outboard maker. The early direct injection 2-stroke models were a major headache for everyone, for example. In my opinion, it was all in the name of me-first competition, and in the beginning both builders and consumers were the losers.

Keep in mind that eliminating the model year concept will not affect warranties. They start only when the consumer buys the engine, not when it is delivered to the dealer. A good illustration on how this works is the Yamaha 90 hp 2-stroke. This very popular engine has changed very little over the more than 20 years it has been on the market. Like all outboard builders, Yamaha has made running improvements throughout the life of this engine, such as better corrosion-resistant finishes and construction materials. Thus as time went on, that model just kept getting better and better. But at the same time I also know of several 90s that were built in the late 1980s and still going strong today, in spite of only being used in saltwater.

Eliminating the model year concept is not without some drawbacks. Because of the pre-
ponderance of auto financing, which is based on the model year for car loans, the finance industry is somewhat confused about making non-MY loans. There have also been reports of confusion among some outboard dealers. Likely this will soon pass as the NO-MY concept gains acceptance, including among the current hold-outs at the manufacturing level.

Contact: Yamaha; www.yamaha-motors.com.