We've presented a few of the most debated outboard motor questions to the experts and here's how they answer them.
For many kinds of boating, the outboard motor is the answer. But it comes with questions, too — which is better, two strokes or four? What's the right prop? Is the bigger motor the better motor? We've presented a few of the most debated questions to the experts, and here's how they answer them.
Question: Are four-strokes always better than two-strokes?
Answer: Are Fords better than Chevrolets? Paper better than plastic? When it comes to outboard power, the question is four-stroke vs. two-stroke. If you believe what you hear, the answer is etched across the stone board — four-strokes rule. But dig deeper and you find the answer isn't so clear.
First, the technical distinction. Four-stroke outboards, like the engine in the car in your driveway, burn straight gasoline within cylinders, circulating lubricating oil through a separate system. Oil and gas don't mix, unless there's a breakdown. Two-stroke engines, in contrast, burn a blend of gas and oil.
Traditional two-strokes were fed their oil-gas mix fuel by carburetor or injector into the cylinder through an intake valve. During part of this feeding, the exhaust valve was also open, and up to 30 percent of the fuel escaped unburned.
Jump ahead to two-stroke direct-fuel-injection (DFI) engines. The fuel is sprayed into the cylinder with precision timing while the piston covers the exhaust valve. There's no loss of fuel. (In four-stroke engines, thanks to their four piston strokes per cycle, intake and exhaust take place at separate times.) DFI two-strokes and four-strokes both deliver much better fuel economy than traditional two-strokes, since they're directed by computer and burn virtually all of the fuel. Evinrude's E-TEC two-stroke DFI engines inject fuel twice as fast as standard direct injection, even adjusting the fuel delivery and oil-gas mix as needed. We've tested the E-TEC engines, and they're just as smooth and almost as quiet as four-strokes while maintaining more traditional two-stroke power.
On the other side, four-stroke motors are also erasing what was a clear division just two years ago, the one that said two-strokes are inherently more powerful. The industry once envisioned a 100 hp limit for four-strokes because of their extra weight. But the limit has vanished. Witness Suzuki's new 300 hp, at just 604 pounds.
"It's a closer call than ever before," says Mercury spokesperson Eric Pope. "The biggest myth is the idea that two-strokes are noisy, smelly and not very fuel efficient. It isn't true today." Two versus four is now more a matter of boater preferences than ground-shaking practical distinctions. Through it all, both modern four-strokes and DFI two-strokes are mechanical marvels. Difference, What Difference?
Question: Are two motors better than one?
Answer: Max horsepower on your boat is 300. Should you install one 300 hp motor or two 150s? You'll mainly see duals (and triples) in offshore fishing applications. In most cases you can bet they've been installed for peace of mind for boaters who have visions of catastrophic loss of an engine at sea. Duals have also earned favor for making docking an easier task, thanks to the engines having props revolving in opposite directions. But for this protection against an unlikely event, and for simpler steering dockside, a boater pays more money upfront — a lot more. Rigging with a pair of motors means you have to duplicate the controls and generally complicates installation.
"In performance, it's a wash," says Suzuki spokesman Rick Hauser. "Three hundred horses are three hundred horses, whether it comes through one prop or two."
So it really comes down to economics. If the price difference is not an issue, then twins are worth considering. Otherwise, a single is the simpler call.
Question: Is high-octane gas best?
Answer: When high-compression engines came on the scene, the increased pressure in their cylinders sometimes caused fuel to explode too early. That preignition, called spark knock, was more than an irritating noise (although certainly that); it caused engine damage. The solution was to add materials to the fuel that would slow the ignition until the piston was ready for the spark plug to activate, which would avoid damage and make efficient use of that higher compression. So now, the higher the octane rating, the better the fuel can handle compression.
Sounds good. But the truth is high-octane fuel — usually 92 or 93 octane — is a waste of money for the majority of outboards. Most are built to run happily on 87 octane. Some manufacturers — such as Tohatsu — do recommend midrange fuel, usually 89 octane. Check your owner's manual, and fuel up with what it prescribes. Go above the recommended octane and you're giving away about 20 to 30 cents per gallon.
Question: Should I rig with the biggest motor allowed?
Answer: Boat buyers years ago were made rightfully leery of boat packages when some dealers priced them with puny outboards, and then coached the consumer up to a more respectable power plant before closing the deal. Those who spent the extra bucks for a bigger motor were generally well-served; those who stayed with a small motor for the lower price point were often disappointed. Things are better now: There are fewer underpowered packages on the market. Still, bigger is generally better. One of the worst things you can do is under-power a boat. You'll never savor the performance built into the hull. You won't be as prepared to scoot from an approaching storm. Potential buyers of your boat down the road will cast a jaundiced eye. Going with the boat maker's maximum rating, found on the inspection plate, is a pretty safe bet. If you're on the fence, you can check with boat manufacturers, who generally have available test data on the boat of your choice powered with various makes and models of engines. Go for the Gusto
Question: Is any prop proper?
Answer: The maker of your outboard probably equipped it with a decent, middle-of-the-road propeller. If not, the dealer likely did. But if either of them installed the perfect prop for you, it was probably dumb luck: The correct prop depends on how you'll load your boat, and how you'll use it. First, some propeller basics. Props are measured in diameter and pitch. You remember diameter from high-school geometry, of course, but pitch? That's the theoretical distance the propeller would travel through one complete revolution if there was no slippage. Moving away from the prop itself for a minute, consider that engine manufacturers rate their product's horsepower at a specific rpm, setting rpm ranges for top-end operation. It can only hit that top-end bracket if it's powering the right propeller. If the prop allows the motor to over-rev, wear and friction can occur. If the propeller restrains the motor from reaching that prime range, it gets poor mileage and you risk other damage. You can protect your motor and improve its performance by picking the right pitch. You can test your prop by running your boat at wide-open throttle. (If you're over the maximum rpm, throttle down until the needle is within the manufacturer-suggested range.) Ashore, inspect the propeller to learn its pitch. Figuring that you get about a 200 rpm drop for each increase in pitch, try a different prop. A cupped propeller will also reduce rpm by about 200. Some dealers will even let you test a prop, provided you return it undamaged and promptly. As long as it hits but doesn't exceed the motor's top-end range, a prop delivering wide-open rpms toward the bottom of the range provides stronger hole shots, while those toward the top generate slightly higher top speeds.
Question: Are outboards maintenance-free?
Answer: There is little you need to do to maintain a modern outboard — but what is still needed is vitally important. You can blow up an engine by neglecting its cooling needs, clog it up by ignoring potential fuel problems, bust it up by letting the lower unit sit over winter with leaky seals. Depleted zincs can invite corrosion. Dinged props can shake the stuffing out of bearings and other moving parts. Owners manuals have slim maintenance sections. That doesn't mean they're unimportant. Maintenance Mantras
How to get home when your boat's steering fails you
From Boating Magazine. By Kevin Falvey Posted Oct 10th, 2014 at 3:48pm
I once steered a boat from 20 miles offshore, through an inlet, and then proceeded down a winding channel all the way to my marina. Some of you might think of this feat as no big deal. But let me reveal that the task was accomplished using a landing net.
After a morning of drift-fishing, my dad and I fired up the engine to head in, only to discover that the cable steering had locked up tighter than a clam. “Get the paddle,” said Dad.
With 20-something nautical miles to the sea buoy, I looked doubtfully at the paddle hanging in the cuddy. But I had misunderstood the old man’s reasoning. He intended that we’d use the paddle as a rudder, not for propulsion. (insert light-bulb over head.)
He put the engine in gear and I dropped the paddle over the side. The boat turned, but the force against the blade was so strong I couldn’t hold the paddle for very long. So we tried the net.
With the hoop end of the net in the water, and me riding side-saddle on the gunwale, I placed my foot against the hoop’s frame and held on to the handle. My leg muscles were stronger than my arm’s, and the water passing through the net provided enough resistance to create direction change even at somewhat higher speeds. Control was imprecise, what with me having to shift sides as we “oversteered” first one way and then the next.
But three hours of S-turns later, we were in front of our marina. Now, not everyone can use a net to steer a boat. Some boats and some conditions won’t allow it. The incident taught me that it’s imperative to have a backup steering plan. For inboard boats, a tiller can be fashioned that connects to the rudderpost. This enables steering by stationing a crew member in the engine room. It may even be possible to fabricate a vertical extension of the rudderpost that extends above cockpit level to which the makeshift tiller can be attached. We’re talking pipe and/or lumber here; nothing fancy.
Outboard-, sterndrive- and pod-powered boats require a different setup. I have seen the aftermath of a gaff handle, duct-taped to an outboard’s cowling, having been used as a tiller. It got the boat home, but the cowling was toast (and may not have held up at all had the seas been rough). So for any boat, I suggest the bridled bucket as emergency steering gear.
You can make your own by cutting the bottom off of a drywall-compound bucket and replacing the wire handle with a handle made of stout line. Next, make a bridle with a length of line that’s twice the beam of your boat by tying the bucket to the middle of this line and each line end to corner cleats, transom ring or other sturdy, “tow worthy” deck fittings.
To use the bucket, simply shorten up the bridle on the side you need the boat to turn. Build the thing and practice with it. You may be surprised how much control it will give you.
At the least, you’ll impress the hell out of the towboat captain or good Samaritan who arrives after hearing your call of lost steering.
Quick Tip: Rudimentary knowledge of disconnecting a steering system will be needed before you can use a makeshift steering system.
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