Features October 1, 1998 Issue

Yamaha 2.0, Merc 3.3 Our Picks Among Tiny Outboard Motors

All six small outboards we tested have their good points, but we especially like the Yamaha 2.0 for its price and quiet, efficient running, and the Mercury 3.3 (and clones) for its forward-neutral shift.

A few years ago there were more than a dozen small outboard brands to choose from, including Mighty Mite, Tanaka, British Seagull, Suzuki and the featherweight champ, the 12-lb., 1.5-hp. Cruise 'N Carry. Today, only eight brands remain: Evinrude, Johnson, Honda, Yamaha, Nissan, Tohatsu, Mercury and Mariner, which nevertheless seem to offer a respectable number of models, with a total of 16 different combinations.

That seems like a lot of choices until one notices that a number of these brands are virtual clones of some of the others. For example, Tohatsu offers 2.0- and 3.5-hp. designs, but except for the paint job and other minor differences these same engines are sold as Mercury, Mariner and Nissan. Outboard Marine Corporation (OMC) sells identical designs under both Johnson and Evinrude labels. In fact, only Honda and Yamaha make and sell their own tiny outboards with no siblings.

In the final analysis, what the small-engine market comes down to is a mere six models: Yamaha 2.0, Honda 2.0, OMC 2.0, OMC 3.3, Tohatsu 2.5 and Tohatsu 3.5, with the latter available either with or without a forward/neutral shifter. The Tohatsus are also sold as Nissan engines, with the 2.5 and F-N shift model 3.5 also marketed as Mercury and Mariner, rebranded with no substantive mechanical differences. In this connection, don’t assume that the Tohatsu 3.5 has more usable horsepower than its clone, the Mercury 3.3, just because it lists a higher horsepower in its advertising. The two engines have identical cylinder bore, stroke, and general configuration, and therefore should perform about the same.

What We Tested
We checked discounted prices on each of the 16 combinations of brand and model, looked for differences in warranty, and arranged to acquire and scrutinize a sample of each of the current six designs representing the 16 combinations. Strictly for convenience we chose for testing an Evinrude (instead of Johnson) 2.0 and 3.3, a Mercury (instead of Tohatsu, Nissan or Mariner) 2.5 and 3.3, a Yamaha 2.0, and a Honda 2.0.

How We Tested
For each engine, we looked for good and bad features and measured performance using a new 7' 6" Quicksilver QS-230 air-floor inflatable as a test bed. We followed manufacturer break-in instructions and were able to operate each motor at top speed.

What We Found
All the engines had several features in common:

1. All have one cylinder, are water cooled (except for the Honda, which has an air-cooled cylinder supplemented by water-cooled exhaust), and work on a two-stroke cycle (again except for the Honda, a four-stroke).

2. All give excellent gas mileage. The relatively small amounts of fuel used, plus the integrated fuel tanks and lack of a way to tap into the fuel system, precluded our doing an accurate test of fuel flow using standard fuel-flow test equipment. However, considering that every engine ran significantly longer than an hour on a single tankful of fuel, even during break-in, and that all the tanks were very small (from .26 gallon for the Honda, up to .40 gallon for the two OMC s), we can estimate that most of the engines perked along at around 10-1/2 to 15-1/2 nautical miles per gallon (or about 12 to 18 statute miles per gallon).

3. None of the tested engines had enough power to sustain a plane on the little Quicksilver inflatable, even with only one 150-lb. occupant. The bigger Merc 3.3 and Evinrude 3.3 came close, moving the boat at close to five knots, bow high in the air, carving a deep hole in the water and leaving a sizable wake, but with not quite enough power to “climb out of the hole” under their own steam.

4. Controls on all the engines are conveniently located and generally easy to use. All include manual pull-cord starting with auto-rewind, an easy-to-operate manual choke, and have a four-position trim-and-tilt system. (The top-mounted starter lets you pull either straight ahead or from an angle on every unit.) All use 360° steering in place of reverse gear, and have no neutral gear position, except the Mercury 3.3, which has a F-N lever. The engines we didn’t test, the Nissan 3.5 and the Tohatsu 3.5, virtual clones of the Mercury 3.3, are available both with and without the F-N feature.

Practically all controls are mounted on the front of all the engines and seem to be remarkably similar in size, shape and placement. All have stop buttons, but only the Honda and two Mercs have lanyard safety stop switches—an important feature, though we doubt many use them. All have a hole to attach a safety line, and all but the Honda have transom screw clamps with holes in their handles, sized to fit a standard padlock, for security.

5. All use a three-blade plastic propeller (though diameter and pitch vary slightly); and all have at least one spare cotter pin and shear pin stuck somewhere on the engine in a rubber carrier, either inside or outside the engine cowl. Each has a ventilation plate just above the prop, about 3.5" wide and from 7" to 9" long, of various oval or straight-sided shapes, leaving the impression that the design of the plates (perhaps like the design of the props they protect from cavitation) is an art rather than a science.

On or near the plate on each engine is a zinc anode to protect against electrolytic corrosion. The zincs, which are sacrificial and therefore must be replaced after they corrode sufficiently, also vary in size, from approximately 2.5" x 1" on the Yamaha and Honda to a relatively modest 1" circle on the Mercs and OMCs.

6. The Yamaha weighed the least at only 22 lb.; the others all weighed between 28 and 31 lb.

All but two of the engines weighed within a pound of the manufacturers’ specification. The exceptions were the Honda, which weighed in at 31 lb. on our ultra-accurate scale, 3.4 lb. heavier than Honda’s spec; and the Mercury 3.3, which weighed 30.1 lb. compared to the Merc spec of 28.5 lb.

7. All are roughly the same size and shape. Five of the six engines would fit into a rectangular box 15" x 39" x 9", with between 1/2" to 2" to spare inside. The lightweight Yamaha 2.0, measuring a mere 13.25" x 36" x 7" was also the smallest. The relatively bulky Honda 2.0, which can fit length and height into the same box as the others, needs almost 2" extra to squeeze in its 10.8" width.

8. All the engines have similar steering features. They all have steering handles that can be flipped up and over the top to make steering control in reverse more convenient. Most handles can be flipped 270 degrees downward to a vertical position, to minimize space taken up when the engine is stored. However, both of the Mercs have a handle which flips only about 230°, thereby losing some compactness in storage.

All have steering handles that we felt were too short for comfort in the size boat we were using. Another 6" of length would have let us scrunch further forward in the boat, for better trim when moving at top speed. (The more powerful of the engines created major trim problems when running full out—with the boat going bow-up approximately 20°, even with the operator as far forward as possible). Unlike larger outboards, every engine had the throttle control mounted on the engine body, not the tiller.

Every engine we tested had the same steering characteristic when running at idle or near-idle: They all wanted to rotate counterclockwise. If we released the steering handle even for a few moments to make a note on our clipboard, we found ourselves turning in circles. There is a “steering friction adjustment”—a wingnut on each engine that you can tighten to reduce or eliminate this tendency, but when the wingnut is tight enough to keep the engine in position, steering is so tight it’s almost impossible to turn at all. We found this true on all engines, though especially evident on the Merc 2.0.

9. When locked in the “up” position and resting against the tilt lock pin or catch, all the engines except the Yamaha 2.0 and Honda 2.0 drooped the bottoms of their lower units into the water to varying degrees. The worst offender in this respect was the Merc 3.3., which showed silt on its lower unit after sitting overnight on our test inflatable. Every engine except the Honda had a “tilt friction adjustment” (requiring a wrench), which if sufficiently tightened would keep the lower units dry in the “up” position. But manufacturers caution owners not to overtighten, since damage is then more likely if the lower unit hits an underwater obstruction when underway.

10. All except the Honda exhausted their fuel supply in a minute or less after the fuel valve was turned to the “off” position. At idle, the Honda took more than two minutes to empty its carburetor, though less at higher speeds. A short fuel run-out period can be a small but notable convenience if you are in the habit of running out fuel after every use to keep the carb from leaking or fouling, as we are—especially since, without a F-N gear, you may have to keep circling your final destination until the engine stops, and then row home.

11. All engines except the Honda have a hinged snap-down door to gain access to the single spark plug, separate from the engine cover. On the Yamaha and Honda, removing the plug required a socket wrench; with the two OMC and two Merc engines, the plug could be removed with either a simple open-end wrench or a socket wrench.

12. Generally, the engines we tested come with a one-year warranty. Yamaha and Honda extend their warranties to two years—in our view, an indicator of company pride and confidence in its products.

All the engines have roughly similar discounted buying prices, as opposed to manufacturers’ suggested retail prices (MSRPs). We checked prices in Sarasota County, Florida, in May, including both local dealers and national mail-order sources. While MSRPs ranged widely, from $615 for the Mercury 2.5 to $976 for the Nissan 3.5, discounted prices seemed to cluster into two groups. The 2.0- and 2.5- hp. group were discount-priced at $525 to $585, except for the Honda ($690).

Three of the four larger engines, of 3.3 and 3.5 hp, were selling for $600 to $645; the Nissan F-N model (priced at West Marine) had a catalog price of $765—but would be less on sale. We'd guess prices will vary according to time and location, and we'd shop around before buying.

Yamaha 2.0
This engine first came to the U.S. 14 years ago, and has been selling in more or less unchanged form ever since. The Yamaha 2.0 has much to recommend it besides a healthy longevity. At 22 lb. it is by far the lightest of the engines we tested. It is also the quietest, both at idle (73 dBA) and wide open throttle (84 dBA). It is the shortest in all three axes—length, width, and height—so can stow in smaller spaces than any of the other engines. It comes with a two-year warranty. Though high in MSRP, it is second lowest (after the Nissan 2.5) in actual selling price after discount.

When we shut off the fuel at the petcock preparatory to storing the engine, its tiny carburetor emptied within 30 seconds—faster than any of the other engines. And its sliding-bolt system for adjusting trim angle is superior to all the other engines’ adjustment procedures, since it allows adjustment without removing the bolt entirely (and thus possibly losing it overboard), and has a pin to prevent loss of its wingnut.

On the minus side, the Yamaha 2.0 had the least pushing power of the engines we tested, although it was still able to move our Quicksilver QS-230 test bed at an average of close to 4 knots—and none of the engines, even the more powerful Mercury 3.3 or OMC 3.3, could get beyond 4.9 knots.

We noticed a few other things which might bother some people, but which others wouldn’t give a second thought. For example, the Yamaha is not as easy as, say, the Mercs and Evinrudes to pick up with one hand, due to the absence of an adequate handle; it has a mere 1/2" deep finger grip on the “back” of the engine cowl, so you need not only strong fingertips, but also two hands to load or unload it. It has by far the longest break-in requirement: 10 hours of running with 25:1 fuel-to-oil ratio and babying the throttle.

Bottom Line: This engine’s advantages far outweigh its shortcomings compared to its competitors. Consequently, if we were in the market for a small, light, simple, reasonably priced, reliable outboard, and the lack of a F-N shift didn’t bother us, we’d put our money on the Yamaha 2.0.

Evinrude/Johnson 2.0
Along with the Mercs, the OMCs (both the 2.0 and 3.3) had well-placed carrying handles allowing convenient one-hand carrying. Weight of the 2.0 was mid-range — and the only engine we tested that weighed less than the manufacturer’s spec (by a third of a pound). The break-in period is not particularly onerous—three hours, with one to two minute spurts of WOT (wide open throttle) allowed in the second hour. The OMCs had the biggest gas tanks of the group, requiring fewer fill-ups.

But, as with the Yamaha, the hinged, snap-down spark plug cover on the 2.0 and 3.3 is not mentioned in the OMC owner’s manual, so figuring out how to reach the spark plug for normal maintenance could be a challenge to new owners. And the angle adjustment bolt that allows you to change the operating angle of the engine is very difficult to use. Among other reasons, the loose grommet on the end of the angle adjustment bolt, meant to ensure that the adjustment wingnut is not unscrewed right off the end of the bolt and lost overboard, may itself be easily dropped into the water while changing shaft angle. Pinning the end of the bolt instead (as does the Yamaha) would be a big improvement to this system.

Bottom Line: The OMC engines seemed middle-of-the-road to us—neither spectacularly good nor spectacularly bad. Their best feature is their convenient carrying handle, but then the Mercs have the same type of handle. Given a lack of any outstanding features not shared by the other motors, we’d pass them by.

Honda 2.0
The Honda 2.0 seemed to push our test bed a little faster than the other 2.0s, though not with as much oomph as the 3.3s. Although we couldn’t devise an accurate way to test fuel economy, we assume the Honda was better on this score than the other engines, since good fuel economy is a principal virtue of practically all four-strokes. Therefore the small size of its tank (0.8 quart) shouldn’t represent a major concern for most people. Our test Honda also used an easy-to-work catch to keep the motor tilted when stored up and out of the water on the boat—judged easier to use than the sliding lock pins on the other engines. And we liked the package of tools and spares that Honda supplies with each engine.

On the other hand, despite its four-stroke reputation, the Honda 2.0 didn’t seem to run any more smoothly or quietly than most of the two-strokes, and its 31-lb. weight made it relatively hard to heft. The fingertip grip is 1", better than the Yamaha’s but still not a full handle—so you have to use only your fingertips to do a one-hand carry. Also, the presence of oil in a crankcase (since it’s four-stroke) restricts carrying positions, as well as permitting only two acceptable storage positions: Upright, or lying on its starboard side.

All of this may be moot with the introduction of Honda’s new (for 1999) 2.0 model, the BF-2. While we don’t have full data, we understand that the new model will be slightly narrower and shorter back to front, 12% lighter than the current model, have about a 5% faster top speed in a typical small boat application, and run about twice as far on a tank of fuel. The increased range is the result in part of a 25% larger gas tank (1.1 qt. vs 0.8 qt.), but mainly due to improvements in operating efficiency, such as overhead valves instead of side valves on the powerhead. Displacement, oddly, has been reduced from 76 cc to 57 cc.

Ecologists will be pleased to hear that the old Honda 2.0’s pollutant emissions, already tiny compared to two-stroke powerplants, are further reduced on the new model.

The best news, especially for those who haven’t bought a 2-hp. unit because they insist on having a “neutral” if not a reverse control, is that the new model will have a centrifugal clutch that in effect gives a neutral gear position when the engine is idling. And this clutch is coupled with a twist throttle, like on the big engines.

But in a brief trial with a prototype of the new engine, we found that while the centrifugal clutch is a considerable improvement over no neutral setting at all, it’s not the ideal solution. Low-speed maneuvering, especially in windy conditions, can get tricky—either the boat doesn’t respond at all, or it suddenly takes off when you give it gas.

In any case, Honda hasn’t raised its prices for these new features. The engine still lists for $855. It will also be available, presumably at a lower cost, without the twist throttle and centrifugal clutch.

Mercury/Mariner/Tohatsu/Nissan 2.5
The two Mercs jointly win the award for shiniest finish—a mirror-like jet black. With handles similar to the OMC engines, they were easy to pick up and move. The break-in period is not arduous, requiring only the time it takes to use up one tankful (less than two hours worth) of 25:1 fuel, and you can speed up in short spurts toward the end of the period. Like the OMCs, both Mercs share a totally common powerhead, with tuning and rpm differences accounting for the difference in rated power. They both have an easily released latching cowl.

On the negative side, the operating angle adjustment bolt on both Mercs must be removed from one hole and reinserted into another hole, not an easy thing to do when the engine is mounted on the boat. The pin could easily be dropped and lost. We much prefer the Yamaha system,which uses a sliding-bolt arrangement. Though not perfect, at least it precludes loss of the bolt overboard.

The handleless spark plug access door on both Mercs is very hard to open, to the point that we were afraid we’d break something in the process. The owners’ manual just says “open the door” with no hints as to how.

Also, the Merc 2.5’s lower unit, when turned 180° for reverse, suffers from interference against a vertical transom. The reason is an unusually large fillet on the back of the lower unit that interferes with any vertical transom more than 13-1/2" high. Of course, shorter transoms, or ones which angle out sufficiently, wouldn’t be a problem. And you can always “trim out” the lower unit to open up space between prop and boat. But that may result in steering problems or other troubles if the “trimmed in” position is the correct one.

Bottom Line: The 2.5 rated horsepower didn’t seem to translate to higher speed in our performance tests. None of its measured specs or characteristics were outstanding enough to make it our first choice.

Evinrude/Johnson 3.3
Most of the comments made for the Evinrude 2.0 also apply to the 3.3. Top speed wasn’t quite as good as the Merc 3.3 (roughly half a knot difference), but this could have been due to differing wind and wave conditions during our tests. The measured weight of the OMC 3.3 was virtually the same as the Merc 3.3, and 0.3 pounds greater than the OMC’s spec.

Bottom Line: As with the OMC 2.0, we see little on the OMC 3.3 to excite prospective buyers.

Mercury/Mariner/Tohatsu/Nissan 3.3
The big Merc has most of the features—good and bad—described for the Merc 2.5 model. To us, the biggest problem is the large fairing (like the 2.5) above the anti-cavitation plate on the lower unit, which can interfere with the bottom edge of a vertical transom when the motor is turned to push the boat backwards.

The one big plus of the Merc 3.3, compared with all the other models tested, is its F-N gearshift. This feature is also available on the near-clones not tested, the Tohatsu 3.5 and the Nissan 3.5. We rate it as a major convenience for this size motor.

Bottom Line: Mainly because of its F-N shift feature, but also recognizing its relatively good measured speed, we’d choose the Merc 3.3 (or one of its F-N shifting clones) if we were in the market for a 3.0- to 3.5-hp. outboard in the under-30-lb. category.

Although all of the tested outboards had some attractive features, we felt that two of them stood out. The Yamaha 2.0 eminently fits the bill for shoppers looking for a reliable small engine that’s light enough at 22 lb. to easily be moved from dinghy to boat and back, and also is easy to stow. It performs well, running quietly, and has no bad habits. It does, however, lack a neutral.

Among the larger units, the Merc 3.3 (or any of its clones equipped with F-N shifting) would be our choice if we didn’t have a weight or space problem storing the engine, wanted the control obtainable with F-N shifting, and didn’t have a boat with a vertical transom that would interfere when the engine was turned 180° to point the boat in reverse. Among the other motors, our decision would come down to price.

Contacts- Evinrude/Johnson, OMC, 200 Sea Horse Dr., Waukegan, IL 60085; 800/998-9960. Honda Marine, 4475 River Green Pkwy., Duluth, GA 30136; 800/426-7701. Mercury/Mariner, Box 1939, Fond du Lac, WI 54936; 414/929-5000. Tohatsu/Nissan, 1420 Valwood Pkwy., Carrollton, TX 75006; 214/243-7981. Yamaha Marine, 6555 Katella Ave., Cypress, CA 90630; 714/761-7612.

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