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]
| 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 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 number of well known riders have chosen this as their go-to bike, such as AMA Champ Dom Barbuto and his brother Nick Barbuto, X-Games medalist Kyle Ford, and StinkBike Racing's own local Seattle legend Joey Merkin. Also, 11-time Nationals winner and rival of Eli Tomac, Richard Rich
References
edit- ^ a b "Two-Stroke Shootout: KTM 125SX Vs. YAMAHA YZ25". Motocross Action Magazine. 19 November 2016. Retrieved 6 May 2019.
- ^ a b 2010 YZ125 Specs, Yamaha Motor Corporation, USA, archived from the original on 2009-11-25, retrieved 2009-12-05
- ^ "MXA's 20 Most Frequently Asked Questions". MotoCross Action Magazine. Archived from the original on 27 February 2010. Retrieved 6 May 2019.
- ^ "EVERY CHAMP | Motocross Action". Archived from the original on 2012-09-05. Retrieved 2007-05-09.
- ^ "10 Things You Might Not Know About The YZ125". Dirt Bike Magazine. Retrieved 6 May 2019.
- ^ "2016 YAMAHA YZ125 Two-Stroke Race Test: Everything You Need To Know". MotoCross Action Magazine. 18 April 2016. Retrieved 6 May 2019.