The Best Motor for My Boat
Choosing an outboard shouldn’t happen until you have a serious discussion. With some experts. Like yourself.
The owner is the only one who knows how the outboard motor will be asked to perform, and where it's going to operate. We all know tournament anglers have different needs and preferences than weekend warriors and anglers with big families. But whether it's a high-performance bass boat or a pontoon, we all want to know how to select the right outboard motor with the perfect prop, the correct shaft length, the optimum amount of power, and the proper rigging. And everybody wants to save money on gas and oil.
Mr. Ry Landry addresses those concerns for people all the time. It’s his job. Landry is Product Education Manager for Yamaha Outboard Motors, where he’s been working for the past 11 years. “I’m responsible for product information that’s not service related,” Landry said. “That involves talking to consumers and the media, doing internal training, and training for OEMs.”
One of the first decisions an owner is looking for is reliability. It is one of the top concerns of all outboard customers. "Reliability starts here," Landry said. "That's our motto. We're pretty confident in our reliability. I was just in Belize where all the outboards you can find are Yamaha, and most have high hours of operation. Commercial fishermen, water taxis, fishing guides, tour guides—most all of them have Yamaha engines." Reliability is why so many lodges up in Canada have switched to Yamaha engines over the past decade. Getting a mechanic up there or transporting a motor for repairs can be very expensive.
The next and much easier decision to make in today’s market is choosing between a 2-stroke and a 4-stroke, Landry says, is easier than picking a prop. "We don't see many 2-strokes these days," he said. "Yamaha, Suzuki, Honda, and Mercury don't have 2-strokes anymore. Only Evinrude has it. The advantage of the 4-stroke is power. The torque curve is beneficial during the hole shot and midrange cruising, with great fuel efficiency. All of Yamaha's portables from 2.5 up 25 HP are 4-strokes today.
Fuel efficiency is a hot topic and another concern Landry often discusses with consumers. "It's easier for engineers of cars than engineers of boats," he said. "Internal combustion burns so much air to burn so much fuel to produce so much torque. So, it's a mechanical thing. Yamaha engineers looked at the design and shape of the lower unit in the water to reduce friction, and we now have the most efficient lower unit we've ever had in terms of displacement. Measuring friction—drag analysis—is done on computers. Engine design has also increased the compression ratio on some of our engines from 9.6:1 to 12.2:1—a significant improvement in fuel efficiency. Other technologies have helped, too."
A new technology from Yamaha to help with fuel efficiency, on select models, is replacing conventional steel cylinder walls with plasma fusion—a micro-textured surface that's 60 percent harder and lighter than steel—means increased displacement without increasing powerhead size, less weight, and decreased friction, all of which increase fuel efficiency. If deciding between new and used—new may cost more but should have better fuel efficiency, saving money over time.
The next consideration would be to figure out what performance you are looking for. "Powering a boat is a tough thing," Landry says. "Water provides a lot of resistance. Far more than air, so it takes far more power to get a boat up to 60 mph than a car. So, choosing the right outboard motor for your boat isn't something to take lightly. Talk with a Yamaha dealer, whether buying there or not. Tell the dealer what the boat will be doing most and where it will be used. Is it a family boat? Fish alone a lot, or with friends and family? How fast do you need to go? Will you be pulling a water skier? Ask, a Yamaha dealer will help you prioritize what you want from a motor and a boat."
One of the newest challenges for prospective outboard buyers is choosing between mechanical and digital controls. "If it's a new motor, one nice option to consider is digital controls," Landry said. "Mechanical controls are good old-fashioned cables for steering and speed. Digital has no cables, just sensors, and wires. Digital controls transmit signals to the engine. The engine's computer instantly processes speed, steering, trim, and other signals. Without cables, a boat has some room for other kinds of rigging. Some people prefer mechanical, though, so control options are something to think about."
A tiller handle is a manual control that comes standard on most portable models and can be added up to a F115. But to have the choice of digital or mechanical on a larger unit, you need to pick a motor that has the capability you want. The Yamaha V6 4.2L engines and I-4 4-stroke engines for instance, are available with either mechanical or digital controls.
A famous boat rigger once told me the average walleye boat he rigged had more electronic density than the fighter jets he worked on in the Navy. That was more than ten years ago and electronic density has increased tremendously. If you're part of the bass world, you want a motor with a decent alternator. Alternators on Yamaha V-MAX SHO models, put out 46 amps at 1000 rpm and 50 amps between 2500 and 6000 rpm. You can power a full array of depth finders, GPS units, and radar with that much power. If electric accessories are your thing, ask about amp output on the motor being considered.
Some people get confused about the shaft length required on the lower unit. The cavitation plate, directly above the prop, should be even with the bottom of the transom pushing both prop and skeg below the hull. Shaft length on an outboard is measured from the inside top of the mounting bracket to the bottom of the cavitation plate. Any transom that measures 14- to 17-inches requires a 15-inch "short shaft" outboard. A 17- to 18-inch transom could go with a 15- or 20-inch shaft, depending on how it's mounted. Any 19- to 22.5-inch transom is best fitted with a 20-inch "long shaft" outboard. And a transom 22.5- to 27-inches tall should be matched with a 25-inch "extra-long shaft." (Yamaha F-Series outboards now offer the option of an "extra-extra-long" 35-inch shaft.)
"Making sure you get the right shaft length can be as easy as talking to the dealer," Landry said. "Transoms have different holes for adjusting the height of the engine up or down. Those additional holes for bolting the motor on can be used to level the anti-ventilation (cavitation) with the bottom of the hull, but positioning can get tricky. It depends on how and where the customer is planning on using the boat. In the Texas gulf, many boats need jack plates to raise and lower the engine because they fish in very shallow water."
Tell the Yamaha dealer where you plan on using the outboard. If buying from a private owner, consult a Yamaha dealer anyway—so that the setup is consistent with the way you boat and fish.
The final choice to make is one that takes in a ton of factors. “Picking a prop requires careful consideration,” Landry says. “Talk to the dealer of the brand of boat you have or go to yamahaoutboards.com. We have a prop configurator that allows you to type in your boat type, length, and weight so you can pick a prop that fits specific needs a little better. It also helps a customer figure out what they need for better speed, a better hole shot, or better fuel efficiency during the type of use the engine will see most. Then they can start looking at things like a 3-blade versus a 4-blade prop, or whether it should be a ventilated prop."
Check out yamahaoutboards.com for answers on brand new product, prop selection, rigging, maintenance requirements, new technologies and more. You’re the expert for your needs, so you might as well own it. Now that you know a little more about how to choose the best outboard for you, use it to purchase your new outboard.