A flat-four engine, also known as a horizontally opposed-four engine or boxer engine, is a four-cylinder piston engine with two banks of cylinders lying on opposite sides of a common crankshaft. The most common type of flat-four engine is the boxer-four engine, each pair of opposed pistons moves inwards and outwards at the same time.
Yamaha Motor Co., Ltd. is a Japanese mobility manufacturer that produces motorcycles, motorboats, outboard motors, and other motorized products. The company was established in the year 1955 upon separation from Nippon Gakki Co., Ltd. and is headquartered in Iwata, Shizuoka, Japan. The company conducts development, production and marketing operations through 109 consolidated subsidiaries as of 2012.
The Honda XR series is a range of four-stroke off-road motorcycles that were designed in Japan but assembled all over the world.
In automotive engineering a multi-valve or multivalve engine is one where each cylinder has more than two valves. A multi-valve engine has better breathing and may be able to operate at higher revolutions per minute (RPM) than a two-valve engine, delivering more power.
The Yamaha YZF-R1, or simply R1, is a 998 cc (60.9 cu in) sports motorcycle made by Yamaha. It was first released in 1998, undergoing significant updates in 2000, 2002, 2004, 2006, 2007, 2009, 2015, 2018 and 2020.
The Yamaha XS650 is a mid-size motorcycle made by Yamaha Motor Company. The standard model was introduced in October 1969,and produced through 1979. The "Special" cruiser model was introduced in 1978 and produced through 1985. The XS650 began with the 1955 Hosk SOHC 500 twin. After about 10 years of producing 500 twin, Hosk engineers designed a 650 cc twin. Later the Hosk company was acquired by Showa Corporation, and in 1960 Yamaha had bought Showa with Hosk's early design of 650 cc twin.
The two-stroke power valve system is an improvement to a conventional two-stroke engine that gives a high power output over a wider RPM range.
The Suzuki RGV250 was a Suzuki high performance sport bike which had a great number of its features and design cues based on Grand Prix technologies and ideas. It is a race-replica based on Suzuki's 250 cc (15 cu in) GP bikes from 1987 to 1998, the RGV V-2 racer. This motorcycle replaced the RG250 Gamma, which employed an alloy frame with a two-stroke parallel twin engine. The bike produced over 60 bhp in a narrow power band between 8,000 and 11,000 rpm. The dry weight ranged between 128 kg (282 lb) (1989) to 140 kg (309 lb) dry weight.
The Yamaha RZ350 is a two-stroke motorcycle produced by Japanese motorcycle manufacturer Yamaha between 1983 and 1996. Available in the US from 1983-1985, Canada until 1990 and Brazil until 1996. The RZ was the final evolution of the popular and well-known series of RD Yamaha motorcycles, and as such is also known as the RD350LC II or RD350 YPVS.
The Suzuki GSX-R750 is a sports motorcycle made by Suzuki since 1984. It was introduced at the Cologne Motorcycle Show in October 1984 as a motorcycle of the GSX-R series for the 1985 model year.
The Yamaha XS Eleven motorcycle, also called XS 1100 and XS 1.1, is a Japanese standard produced from late 1977 (MY1978) to 1983, powered by an air-cooled 1,101 cc (67.2 cu in) 4-stroke, DOHC inline four-cylinder engine mounted transversely in a duplex cradle frame with swingarm rear suspension, shaft drive, and telescopic forks.
The Yamaha FZR1000 is a motorcycle produced by Yamaha from 1987 to 1995. Classed as a sports motorcycle.
The Yamaha TDR250 was a street-legal middleweight dual-sport bike produced by Japanese motorcycle manufacturer Yamaha between 1988 and 1993.
The Yamaha YZ250 is a two-stroke motocross race bike made by Yamaha. The model was launched in 1974, and has been regularly updated and is still in production with new releases every year.
The Yamaha YZ450F is a four-stroke racing motocross bike built by Yamaha Motor Corporation. It was the successor to the previous YZ426F which was discontinued in 2003. It is credited by Cycle World and Dirt Rider magazines as the bike that started the four-stroke dirt bike revolution. The 2006 YZ250F and YZ450F were the first production motorcycles equipped with titanium suspension springs.
The Yamaha RD500LC is a high-performance, two-stroke sports motorcycle, also known as the RZ500 in Canada and Australia. A lightened but detuned version known as the RZV500R was developed for the Japanese home market. Strict United States Environmental Protection Agency regulations meant that the RZ500 was not available for sale in that country. Produced for a short period between 1984 and 1986 it has become a sought after collector's machine.
The Yamaha FZ750 is a sports motorcycle produced by Yamaha Motor Corporation between 1985 and 1991. The FZ750 is notable for several reasons, perhaps the most radical being the 5-valve cylinder head with a radial arrangement. This became something of a Yamaha trademark. The FZ750 would be the first bike in the Genesis design concept.
A big bang engine has an unconventional firing order designed so that some of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing, changing or re-timing the camshaft, and sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because a big-bang engine has uneven power delivery, they tend to run rougher and generate more vibration than an even-firing engine.
The Kawasaki KR-1 and KR-1S are road-orientated 249 cc (15.2 cu in) two-stroke sports bikes introduced between 1988 and 1992 by Kawasaki Heavy Industries.
The Yamaha TZ 250 was a commercially available racing motorcycle with a watercooled, two-stroke, 250 cc engine produced by the Japanese manufacturer Yamaha.
