Yamaha Y125Z

{{Infobox Motorcycle | name = Yamaha Y125Z / Yamaha Y125ZR | image = | aka = One tupai | manufacturer = Yamaha Motor Company | parent_company = Yamaha Corporation | production = 1998 – 2017 | predecessor = Yamaha Y110SS / Yamaha Y110SS Two | class = Kapcai| engine = 124.3 cc air-cooled, 2-stroke engine
Cylinder Arrangement = Forward inclined single cylinder
Bore & stroke = 53.8 x 54.7 mm | power = 17.5 HP (13 kW) @ 12,000 rpm | torque = 1.85 kg·m (18.1 N·m/13.4 ft·lbf) @ 7,500 rpm | transmission = 6-speed | suspension = Front: Telescopic fork
Rear: Monoshock swingarm | brakes = Front: Disc
Rear: Disc | Frame = Twin steel tube | tires = Front: 70/90-17 38P
Rear: 80/90-17 44P | rake_trail = 27° / 82 mm (3.2 in) | wheelbase = 1,250 mm (49 in) | length = 1,900 mm (75 in) | width = 675 mm (26.6 in) | height = 1,035 mm (40.7 in) | seat_height = 752 mm (29.6 in) | dry_weight = 101 kg (223 lb) | wet_weight = | fuel_capacity = 5.5 L (1.5 US gal) | related = Yamaha Y110SS/SS2

Yamaha Y125Z or 125ZR or better known as Yamaha Tupai in Malaysia, is a 125 cc two-stroke moped or underbone motorcycle produced by Yamaha. Debuted in 1998 as a successor of the Yamaha Y110 SS/SS2, the Y125Z was the first two-stroke underbone motorcycle with an YEIS catalytic converter. Beside being sold in most Southeast Asian countries mostly in Malaysia and Singapore, it was also sold in Greece. The 125Z became the 125ZR in 2004 when an all new coverset came out with the 'GO!' livery derived from Valentino Rossi's MotoGP racebike. The production of the Y125ZR ended in 2017 after being sold for more than two decades.

Yamaha Y125Z in motorsports

The Yamaha Y125Z is widely used in motorcycle racing tournaments held in Malaysia or Asean level. In Malaysia, the Y125Z is formerly used in the Expert category of Malaysian Cub Prix tournament series.