Yamaha RD125LC

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Yamaha RD 125LC
Production 1981 - 1986
Class Classic
Predecessor Yamaha RD125
Successor Yamaha RDZ125
Single cylinder, two stroke, liquid-cooled
Bore / Stroke 55.9mm x 55.9mm
Compression ratio 6.4:1
Top Speed 81 mph
Horsepower 19.98 HP (14.9 KW) @ 9500RPM
Torque 11.8 ft/lbs (16.0 Nm) @ 9250RPM
Transmission Gear box: 6-Speed

Final Drive: Chain

Clutch: Wet multi-plate
Suspension Front: Telescopic fork
Rear: Monocross linkage
Brakes Front: Single disc 245 mm
Rear: Drum
Front Tire 2.75-18
Rear Tire 3.00-18
Wheelbase 50.98 inches (1295 mm)
Length 78.31 inches (1989 mm)
Width 28.9 inches (734 mm)
Seat Height 30.51 inches (775 mm)
Weight 110.0 kg (wet)
Recommended Oil Yamalube 10w-40
Related Yamaha RD200, Yamaha RD250LC, Yamaha RD250
Manuals Service Manual

The Yamaha RD 125LC was a Single cylinder, two stroke, liquid-cooled Classic motorcycle produced by Yamaha in 1981. Max torque was 11.8 ft/lbs (16.0 Nm) @ 9250 RPM. Claimed horsepower was 19.98 HP (14.9 KW) @ 9500 RPM.


MK1 125LC. If you have a pic of a missing color then please do feel free to mail it to me. I cant do this site with out your help, and it is very much appreciated CHEERS.In the summer of 1982 the RD 125LC was unleashed on the UK learner market. It was the successor to the Air coold RD125 twin. They put a sporty bikini faring and bellypan on it as standard. Even though this 125 was restricted to 12 bhp and 75 mph with a micron or allspeed (the pipes of choice at that time) it could see just over 100mph on the clock down a good hill. With a cantilever mono-shock swining arm italic style wheels It addopted from its big brother the 250lc and a single cylinder water coold engine it realy did look the biz. They just flew out the dealers shops.

MK2 125LC. In 1985 yam updated the 125LC with the MK2. Theys had rounded clocks replacing the dated rectangular ones of the MK1. It had better thiker forks, clipons with bare ends. Gone where the famous itilic wheels swoped for straight spokes, puting 16 inch front wheel on it with and a braced front mud guard and a diferent disk and an aposed piston brake caliper, this improved the stability and handeling and braking. The wheels looking very simuler to the 350YPVS now on the market. At this time there were quite a few 125's chomping at the lc crown the RG, NS, MBX, MTX , KMX, AR and yams own DT all sharing the sales.

MK3 125LC. Yamahas next model the RDZ125 MK3 was unvaled in 1987. This model was under a lot of compertishon from the aformentioned bikes and was basacaly just a stop gap while the TZR125 was being finished of. The emphasis was on the motor with no real changes to the bike its self. It was fitted with a YPVS engine simuler to the one being used on yams DTR125. It had a very nice looking exhourst resembeling the F2 350 YPVS pipe and the pipe fited to the still to come TZR125. The powervalve was blanked of for the UK lerner market, but you could get a powervalve kit to get it runing, if you did boy did they fly. I sell loads of theys kits for MK3 125's and TZR's you get all the bottom end with all the top end to as the valve opens up and you get the full BHP to the back wheel. In Europ this model was known as the Mk2 LC2 not the Mk3 There bikes had a working YPVS


A 55.9mm bore x 55.9mm stroke result in a displacement of just 123.0 cubic centimeters.


The bike has a 6-Speed transmission. Power was moderated via the Wet multi-plate.


It came with a 2.75-18 front tire and a 3.00-18 rear tire. Stopping was achieved via Single disc 245 mm in the front and a Drum in the rear. The front suspension was a Telescopic fork while the rear was equipped with a Monocross linkage. The wheelbase was 50.98 inches (1295 mm) long.

Yamaha RD 125LC Specification[edit]

  • Introduced: Mk1 August 1982 .......... MK2 June 1985 .......... MK3 March 1987
  • Discontinued: MK1 March 1986 .......... MK2 March 1987 .......... MK3 February 1989
  • Frame/engine nos: Mk1 10W- 000***/ 1984 Then 12A 100*** 1986
  • Frame/engine nos: Mk2 1GM -000***
  • Frame/engine nos: Mk3 2HK 000***
  • Colours: Mk1 White with red decals, White with blue decals, Candy blue with grey decals and in 1984 Red with white decals.
  • Colours: Mk2 White with red decals, Black with red decals
  • Colours: Mk3 White with blue decals. Plus the 2 above.
  • Bore and stroke: 56mm X 50mm
  • Capacity: 123cc
  • Power: 12bhp standard restricted ......... 21bhp derestricted
  • Gears: 6
  • Wheels: MK1 18-inch front and rear.......... MK2&3 16-inch front 18-inch rear
  • fuel capacity: 2.86 gallons
  • Speed: 75 mph Standard .......... around 95 mph derestricted
  • Weight: 210 lbs
  • mpg: 65 standard down to 45/50 derestricted

1981 - 1986 Yamaha RD 125LC[edit]

1981 - 1986 Yamaha RD 125LC 1981 - 1986 Yamaha RD 125LC 1981 - 1986 Yamaha RD 125LC 1981 - 1986 Yamaha RD 125LC 1981 - 1986 Yamaha RD 125LC

Yamaha have incorporated all the virtues of the phenomenally successful RD 250LC and RD 350LC into the RD 125LC.The liquid-cooled 123 cc single cylinder motor incorporates all of the latest developments in two-stroke technology.