Test of 15 hp outboard motors

Over the past few years, we have tested a lot of 15-horsepower outboard engines of various brands. During this period of changing trends and preferences in the motor market, which requires awareness, especially when it comes to such popular size, as powerful enough to take to the water company, and thus portable, suitable for carrying and installing one person forces, maximum two. A set of consumer qualities of outboards that can be evaluated for a limited test time, not too long: specific speed, high-torque, acceleration (acceleration speed), efficiency, ergonomics and noise. It is almost impossible to estimate the resource and maintainability - qualities that the interests of consumers especially active. It calms that modern engines imported usually characterized by high reliability, and resource and reconstruction issues are inevitably reduced to a dealer's choice problem that can best ensure your customer warranty and service. But this is a completely different topic of research. CONSTRUCTION Model ranks companies on the engine builders unequal split on the basis of the constructive branch - eco-friendly and conventional engines - is a known limitation in the use of water bodies in the US and Europe of engines that do not meet the new stringent standards of environmental pollution CAPB and EPA. The consequence of this was the gradual replacement of conventional two-stroke carbureted models motors low-power group with new four-stroke, and although small duple-cycle is still continuing off the assembly line, the process of improvement in the general stopped in the 90th., And therefore, the appearance of them fundamentally new design solutions count, unfortunately, is not necessary. Chetyrehtaktniki "our" size is not follow fashion trends engine, but also for the implementation they are more perfect than the duple-cycle, especially from an ergonomic point of view. We tested four-stroke "Honda" and "Suzuki" comfortable tillers control with a simple adjustment of the efforts of the motor rotation and throttle and easily accessible "Stop" button. Lever inclusion stroke if he fits in your hand and works very well. Mechanisms and otkidki mode "shallow water" are such that the possibility of wet hands in the outboard water is excluded, it does not need the extra movement and also great effort. Two-stroke "Suzuki", "Yamaha", and especially "Selva", the lighter motors deprived poured into the oil sump, winning only one - in the convenience of carrying and storage. An exception here seems, perhaps, "Mercury" with its integrated into the tiller mechanism switching speed and quite modern system otkidki one hand. It deserves respect and a way to fix his propeller lock washer instead of cotter pin, which greatly simplifies the process of installing and removing the screw, especially if it is not on the solid shore, and on shaky wave. Four engines "seek" is not far behind on the weight characteristics of the stroke, but in this fight there are costs: thin-walled castings forces closely monitor the tightness of sealing gaskets, especially in places of passage of cooling the cylinder channels. Therefore, the state of the oil is to monitor regularly, especially during the break-in. Impressive weight chetyrehtaktnika seemingly would lead to an increase in the requirements for ease of carrying it, but to take up the lick "head", for example, "the Honda," the second person (a carry motor better together) is not easy - seizure by the arm on the opposite clamp side too shallow. Four-stroke "Suzuki" in this sense, too, did not shine, but the dealer's representatives assured us that a new model of the motor, in which the carrying ergonomics improved in the past year. What no problems, so it is in the start-up of all the tested engines. It was enough to pump the bulb in the fuel line, and start is not forced to wait long. The only thing necessary to take into account the individual characteristics of each model - the need to include "inflow", the choice of the starting throttle opening, but it is a matter of habit.


Behold motors are equipped with locks to run in gear and stop switch ( "linchpin"), it is only necessary to remember about their presence, and if your engine suddenly refuses to wind up, do not rush to immediately call the dealer if an error occurs.


Runs, measured under six engines (two-stroke "Mercury", "Selva", "Yamaha", "Suzuki" and chetyrehtaktnikami "Suzuki" and "Honda") on an equal footing in the disassembled inflatable boat 3.6 m allowed to compare their speed and traction quality (see. table). The first important observation: the screw, which the company supplies as a "standard" is not always screw on all occasions. Typically, the motor with it "twists" under a small load, the optimum load is provided to approximately 200 kg. The highest speed - 40 km / h - show the push-pull "Suzuki" as the "voluminous" among similar motor, as well as other more "twist" "the Yamaha", which was the fastest at all test loads. From the Italian motors "Selva" We usually wait for high-speed performance, but "Naxos" We did not show them - to say too heavy screw. Apparently, according to high-speed qualities "of Selva-15" was supposed to be somewhere on the level of my classmates, though its course is not further worsened in the wake of the air prohvatit and sharp turns. Four-stroke engines gave way to slightly light, but with two passengers were speedboat last - pull them better and are less sensitive to load, especially "Honda" with its highest volume of the cylinder (350 cm3 302 cm3 against in "Suzuki").


On acceleration speed - as usual, with about the same results, in the lead duple-cycle. Four-stroke "Suzuki" was predictably a little more "thoughtful", "the Honda" also with an increase in the load pick-up had amazing growth compared to the competition, probably due to more developing time and the stop of the complete four-bladed propeller.


On fuel consumption, two-stroke engines, as it turns out, are very close to each other - they consume at full speed test half a liter in about five minutes, ie about 0.38-0.40 l / h on the strength of power... Lags behind in efficiency of Selva, working to the same 95-m gasoline, the result of the Yamaha was a bit better than average, but chetyrehtaktniki were naturally more economical by 20-30 percent, while consuming the same 0.5l already for 6-6.2 min., T. e. 0.32-0.33 l / hp / hr at full speed. Of course, at the intermediate power advantage in fuel consumption have even more, reaching incredible heights in the most low speed when, it seems, the motor is capable of operating just on gasoline vapors. Cost small chetyrehtaktnika regimes has an important side effect - with many hours of work on the angler gets significantly less likely to breathe in harmful exhaust gases.


At long transitions engine noise is important, not less than his other options, as it affects the fatigue sitting right next to him the driver, and the possibility of a normal conversation in a boat on the go. Here it should be noted that all engines tested, regardless of taktnosti, showed about the same high noise at full speed - 90-92 dB. But the noise spectrum turned out to be different in different mo-tors, more or less tolerable to the ear. At Suzuki and especially in Selva in the noise present sonorous overtones, harsh to the ear, the Yamaha is softer, and is therefore not so much interfere with the conversation. At low and medium speed four-stroke engines advantage was also obvious - they worked a few decibels quieter two-stroke. But at Honda have provided a reason the green of the engine fire indicator, or sometimes it would be impossible to determine the sound, it works at idle or not.
Alex Daniaev, photo by Alexander and Dmitri Dobrokhotova Pichkaleva

Source: Supplement to the "Boats and yachts"

November 2007

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