Engineering:Yamaha YZ125
| Manufacturer | Yamaha |
|---|---|
| Production | Since 1974 |
| Class | Motocross |
| Engine | 124 cc (7.6 cu in) reed valve two-stroke single |
| Power | 33.53 hp (25.00 kW)[1] |
| Transmission | 5- or 6-speed sequential manual |
| Suspension | Mono-shock, 13 inches travel |
| Brakes | Hydraulic disc |
| Tires | Front: 80/100-21-51M Rear: 100/90-19-57M |
| Wheelbase | 1,440 mm (56.8 in) |
| Dimensions | L: 2,140 mm (84.1 in) W: 830 mm (32.6 in) H: 1,320 mm (51.8 in) |
| Seat height | 1,000 mm (39.3 in) |
| Weight | 86 kg (190 lb) (dry) 94 kg (208 lb)[2] (wet) |
| Fuel capacity | 7.9 l; 1.7 imp gal (2.1 US gal) |
| Related | Yamaha YZ250F |
The Yamaha YZ125 is a motocross racing motorcycle with a two-stroke 124.9 cc (7.62 cu in) displacement single-cylinder engine made by Yamaha since 1974. It is available to the public. For the first two years it was made with dual rear shocks, then changing to a monoshock.[3] The YZ125 has been ridden to five AMA National Motocross Championships, and multiple AMA Regional Supercross Championships.[4]
In 2001, Yamaha released a bike designed to complement the YZ125, the four-stroke YZ250F. The two bikes shared a rolling chassis and are eligible to compete in the same racing class. The YZ250F has a slight horsepower advantage.[5]
The YZ125 has a 124 cc (7.6 cu in) reed valve-inducted two-stroke engine. It was air cooled from 1974 to 1980, and liquid cooled since 1981. It has a Mikuni 38 mm TMX series carburetor.[6] The engine produces 35 hp (26 kW).[1]
The YZ125 has been built with five- or six-speed manual sequential gearbox depending on model year. The 2005 model has a constant-mesh, wet, multiple-disc coil-spring clutch.
From 1973 through 2004, the YZ125 had a single backbone frame made from steel. It generally averaged from 176 to 198 lb (80 to 90 kg).[citation needed] For the 2005 year, Yamaha switched to a single backbone frame constructed from an aluminum alloy. This frame material change dropped the dry weight to 190 lb (86 kg).[citation needed] For 2008 models, the wheel assemblies and front fork suspension were redesigned, yielding additional weight savings, making wet weight, no gas sub-200 lb. Aluminum-framed YZ125s are notably "flickable" and sometimes this trait is seen as a drawback since they tend to become more difficult to control on rough surfaces.[2] The YZ125 used a conventional telescopic fork tube through 1988, then in 1989, added the first upside-down fork. A very well knows the amount of riders have chosen this as their go-to bike, such as AMA Champ Dom Barbuto and his brother Nick Barbuto, and X-Games medalist Kyle Ford. Also, 11-time Nationals winner and rival of Eli Tomac, Richard Rich
References
- ↑ 1.0 1.1 "Two-Stroke Shootout: KTM 125SX Vs. YAMAHA YZ25". 19 November 2016. https://motocrossactionmag.com/2016-mxa-125-two-stroke-shootout-ktm-125sx-vs-yamaha-yz125/.
- ↑ 2.0 2.1 2010 YZ125 Specs, Yamaha Motor Corporation, USA, http://www.yamaha-motor.com/sport/products/modelspecs/31/0/specs.aspx, retrieved 2009-12-05
- ↑ "MXA's 20 Most Frequently Asked Questions". http://www.motocrossactionmag.com/me2/dirsect.asp?sid=F42B9D67B8404E24AA0EF9B32A75BA62&nm=FAQ%27S.
- ↑ "EVERY CHAMP | Motocross Action". http://www.motocrossactionmag.com/me2/dirsect.asp?sid=9945527E1D6A4953ACE23BB700C838FF&nm=EVERY+CHAMP.
- ↑ "10 Things You Might Not Know About The YZ125". https://dirtbikemagazine.com/10-things-you-might-not-know-about-the-yz125/.
- ↑ "2016 YAMAHA YZ125 Two-Stroke Race Test: Everything You Need To Know". 18 April 2016. https://motocrossactionmag.com/mxa-2016-race-test-yamaha-yz125/.
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