The Outboard Expert: Fuel Economy Secrets

As gas prices soar, even this little can can cost a boater $24 to fill.

High gas prices took some of the fun out of the Memorial Day weekend, which marks the beginning of the pleasure-boating season here in the Midwest. As gas approaches $4.00 per gallon, even owners of small runabouts are looking at a $150 bill for a fill-up. An expert on the radio today said that, adjusted for inflation, we still have not surpassed the peak price for gas, which was posted in 1981. But we are getting real close.

With that dubious record in mind, it would pay to make sure we are squeezing the most outboarding fun out of every ounce of go-juice. Here are some ideas to consider:

Throttle Back: Almost every outboard-powered boat I've tested over 20 years of crunching fuel-flow data has an economy "sweet spot" between 3000 and 4000 rpm. This is usually about the engine speed required to get the boat smartly on plane, but not much faster. At the recent Yamaha media intro, for example, I ran a Skeeter SL 210 powered by the 225-hp F225TLR four-stroke. Best economy was 6.13 mpg at 3000 rpm and about 28 mph. At 4500 rpm, economy dropped by 30 percent, to 4.33 mpg, and it dropped by 60 percent to 3.82 mpg at 5500 rpm. Of course, at that engine speed I was zipping along at 59 mph, which is a lot more fun than 28 mph. All I'm saying is that maybe you don't need to go 60 mph all day.

This reminds me of the multi-engine custom go-fast boat I tested in Miami a few years back that had an analog fuel-flow meter with a face marked to report "dollars per hour." The owner could laugh because he could afford the gas.

Prop It Right: A prop that is too big or too small can really screw up fuel economy. Too much prop pitch can make it hard for the boat to get on plane, and this is when you are using the most gas, just plowing a hole in the water. A boat that is under-propped might get right on plane, but then will require more rpm to run at cruising speed. It's like trying to pedal a bike in the wrong gear - your legs are flying around but you're not getting anywhere. Propping is a subject for an entire column, or a book, but the short version is that you want your boat to be right in the middle of its wide-open throttle (WOT) rpm range at wide-open throttle. If your prop is too small, the engine will over-rev. If the prop is too large, the engine will be stuck below the minimum WOT rpm.

Don't know your motor's rpm range? Check your owner's manual, which probably also has some good advice on prop selection. Lost your manual? Merc and Yamaha have many manuals in PDF format on their websites. Or you can order a new hard copy from your dealer. Don't have a tachometer? Get an inexpensive shop tach at an auto-parts store and use it just for testing your prop.

Love Your Prop: Boating with a prop that has chewed-up blades is like driving a car with a wheel out of balance. You're going wobble-wobble-wobble down the lake. It's bad for efficiency and hard on the prop-shaft bearings. Get your prop fixed or buy a new one. At $4.00 a gallon, a new prop might pay for itself this season.

Trim It Out: Run as much trim as possible for the boat's speed. On most boats, this will lift the bow, which reduces drag in the water. You go faster at the same throttle setting, and gain efficiency. If your boat starts to "porpoise," or bob up and down, you've over-trimmed. Another sign of over-trimming is the sound of the prop breaking free of the water. You can use a hand-held GPS to watch your boat speed as you trim out the motor in small increments. When your speed over the water starts to go down, you've passed the most-efficient trim setting, and some boats take a lot less trim than others.

Put Your Boat on a Diet: Your boat is not a storage unit. If you are carting around broken fishing gear, old bottles of sun screen, rusty tools, Uncle Wally's lucky slalom ski, and two extra anchors, you are also wasting gas. Clear that stuff out of the boat. I've seen fishing boats that could lose 150 pounds in an hour, and it makes a difference.

Clean Your Hull: Marine growth on the boat bottom can cause a lot of drag. If you keep your keep your boat in the water, clean the bottom regularly.

Keep Her Tuned: There's not a lot of tune-up work you can do on a modern, fuel-injected outboard. But older two-stroke motors can benefit from being timed correctly, having the carbs properly adjusted, and being treated to a fresh set of spark plugs. If it's been a few seasons since you've had the old gal in the shop for a spa treatment, find a good outboard tech and get her tuned up.

Tow Slower: If you tow your boat you're getting a double-whammy from escalating fuel prices. You can save some gas by slowing down to the speed limit, and by making sure your tires-truck and trailer-are properly inflated.

Toyota Fishing Website Showcases New Series "Hooked"

Toyota has launched a new website that documents the activities of its pro bass angler team on and off the water. The site includes text stories and a series of weekly webisodes called "Hooked" on www.toyotafishing.com that offers footage of the life of pro anglers away from the water. To create the series, video crews spent nearly a month shadowing the Toyota Tundra Fishing Team members Greg Hackney, Mike Iaconelli, Terry Scroggins, Dave Wolak and Kevin VanDam, from practice at the 2007 Bassmaster Classic to life at home. A new episode of "Hooked" will air every Sunday.

Honda Marine Names First "Master Techs"

Need your Honda outboard serviced? Here are two good men to see. Honda Marine has recognized dealer technicians Anthony Towns of Abel's Marine, Englewood, Fla., and Kenney Meyers of Paradise Marine, Gulf Shores, Ala., as its first-ever "Master Techs" following a series of rigorous tests at Honda's training facility in Orlando, Florida. Thirty-three Honda service technicians were tested on Honda-specific skills including technical processes, maintenance procedures, service diagnostics and repair support resources. Of that group, Towns and Meyers were the sole recipients of the "Master Tech" title. Towns and Meyers will hold the title of "Master Tech" for two years, after which they will be re-tested.

Written by: Charles Plueddeman

Charles Plueddeman is Boats.com's outboard, trailer, and PWC expert. He is a former editor at Boating Magazine and contributor to many national publications since 1986.