Honda introduced new models of outboard marine four-stroke engines BF90 and BF75
With extensive experience in the creation of four-stroke engines for cars and motorcycles the Japanese engine producers were able to adapt quickly to the situation and began to produce four-stroke engines of low and medium power. In a less advantageous situation were the giants of American-made outboard motors “Mercury” and the MLA, which had to rely on the development of two-stroke engines with direct fuel injection. According to experts, such a path is considered optimal for high power motors, as four-stroke engines with capacity of more than 150 hp significantly lose two-stroke models for weight and size characteristics, and therefore may have problems installing them on the existing models of boats. It would seem that the way it is – the most powerful chetyrehtaktnikom in recent years remained “Honda-130” and “Yamaha” has launched a number of models with two-stroke direct injection power of 150-225 hp Nevertheless, in 2001, “Yamaha”, and behind it and “Honda”, presented to the public the new model of four-stroke engines with capacity of 225 hp, raising thus almost 100 hp power limit bar for motors of this type. On the creation of a similar engine running now and engineers “Suzuki”.
On his desire to expand the range of four-stroke outboard motors produced up to 200 hp experts corporation “Yamaha” announced in 1998. The first samples of the new engine were published in September last year and a few months later in the production of a pilot batch was launched, designed for comprehensive testing and test the reliability of components and assemblies news. The fact that motor development has taken more than three years, says the complexity of the problem, which had to deal with the Japanese motorists.
During the design of the motor “Yamaha” abandoned the traditional four-stroke engines “row” engine configuration and created a new unit design with a V-shaped arrangement of cylinders. It should be noted that the same path developed in his time two-stroke engines, and the layout of the new four-stroke power unit “Yamaha” two-stroke layout reminiscent of similar capacity.
Engine “Yamaha F225” has six cylinders arranged V-shaped at an angle of 60 °, a total displacement of 3352 cm3, maximum power outputs at 5500 rev / min. Gas distribution mechanism DOHC with two camshafts in the cylinder head and 24 valves. automotive exhaust system opposite: the flue gas path is located in the collapse of the cylinders, and inlets – the outside unit. This architecture allowed to create enough light and compact unit.
The lubrication system is standard for four-stroke outboard engine: because the engine cylinders are arranged vertically, the lubricating oil can not be in the crankcase. You have to use a separate oil tank in Deadwood under the engine. Oil is supplied to the friction of the oil pump driven by the crankshaft, and is returned to the tank by gravity. There are tank and cooling seawater, which simultaneously cools the exhaust gas, that is effective in reducing motor noise. Cooling water and exhaust maze idling and fuel pump that supplies fuel to the injectors six, individually for each cylinder. Fuel injection is carried out in a specially designed intake pipes, customized for each of the six cylinders.
The process controls the fuel supply electronic control unit ECU engine management, providing optimal ratio of air-fuel mixture and ignition timing at all engine operating conditions. The electronic unit also automatically maintains the idle speed, controls the process of warming and protect the engine from damage when it detects deviations in his work. In addition, the ECU includes a diagnostic system to connect the port to a PC, through which you can track all stages of the work of the engine and its systems to identify potential problems before when the engine will require repair.
Motor F225 afterburning gases distinguishes presence system: falling into the crankcase through a gap between the piston and cylinder gases on wall duct with separator oil fed into the inlets, thereby returning to the engine cylinders, which engage again in the operating cycle. The use of this device is beneficial to the efficiency and environmental performance of the engine.
As a result, the Japanese managed to create an engine that, although it is the heaviest – the weight of 268 kg – outboards in the model number “Yamaha”, but, nevertheless, only 74 kg heavier than the two-stroke carbureted engine “Yamaha” of the same capacity and 32 kg – models with direct injection. At the same time, F225 is much more economical and quieter than its two-stroke “brothers”, and most importantly for the release of hazardous substances into the environment, not only meets the requirements of the existing norms, but higher planned.
On the efficiency and other operational characteristics of the motor can be judged by the results of tests that were able to hold firm – manufacturers of boats, the benefit from the first batch of exit F225 time been almost a year. A comparison of the results of tests of a four engine capacity of 225 hp, two-stroke engine 225 EFI the same capacity fitted with fuel injection into the intake manifold, and a two-stroke engine Z 200 HPDI direct injection 200 hp, all motors production “Yamaha” in the same boat (length 6.3 m, displacement 1500 kg), F225 economical 225 EFI approximately 30% in all modes, as well as less powerful Z 200 HPDI, quieter two-stroke engines in different modes by an average of 10 dBA , has a higher speed and dynamic performance than comparable motors.
Serial production F225 engine began with the June 2001 Motor comes with a height of deadwood 25 or 30 inches (635 or 762 mm). There are versions with left rotation for twin-engine propeller propulsion. In October, started producing dvuhsotsilnoy F200 model.
It is expected that these engines will revive the upper part of the range of outboards, annual global sales of which in recent years is about 800 thousand. Units. The United States considered, where 350 thousand sold in the year as the main market for the new engines. Engines, most of which are rated at more than 100 hp
The hardest thing to predict sales in the European market, where the company “Yamaha” currently owns about 33%, and in some countries such as Scandinavia and Ireland, it dominates. In recent years there has been a growth in sales of this company, and in southern Europe, especially in France and in Italy. According to managers, a lot will depend on what will take the “Bombardier” with MLA residues. Of course, no one is able to quickly fill the gap, but still have “Yamaha” has the opportunity to expand the market.
So “Yamaha” expects to sell in Europe for the year to 500 units F225 / 200 engines. This, of course, a modest figure compared to 70 thousand. Annual sales of the company in Europe outboards other models.
Although the demand for more powerful engines are constantly growing in recent years, the two engine models F225 / 200 is still regarded as exotic. Up to 70% of the engines, which sells “Yamaha” in Europe, like most other engine-building companies have a capacity of up to 25 hp.