Honda MT125R
| Manufacturer | Honda Racing Service Center |
|---|---|
| Production | 1976-1979 |
| Predecessor | Honda CR93 Honda RC149 |
| Successor | Honda RS125R |
| Engine | 125 cc two-stroke single |
The Honda MT125R was a production Grand Prix motorcycle racing roadracer designed for closed-course competition roadracing. It was produced by Honda Racing Service Center (RSC) and made available to the general public. It was also marketed for the U.S. market in the years 1977–1978 through the American Honda Motorcycle dealer network.
For many champion motorcycle roadracers, the road to the top started on a small engine capacity two-cycle motorcycle. Top roadracers like Randy Mamola got their start on a 125 cc GP racer. Others like Ángel Nieto spent their entire careers racing in the 50 cc, 80 cc and 125 cc classes.
Product code: 325
Product code: 325
Expansion chamber redesigned
Good examples of this model will have the original "RSC" tachometer, factory prop stand which lifts at the footrests, owners/service manual.
A liquid-cooled kit was available from RSC which included: liquid-cooled cylinder, cylinder head, water pump, hoses, hardware, temperature gauge and radiator. This option is fairly rare.
The MT125R shares many parts with the CR125 engine. The CR versions were motocross bikes with similar specifications. One notable difference was the shift pattern on the transmission. Both had the standard 1 down 5 up pattern. On MT125R versions the shift lever was flipped over rearward to accommodate the rearset footpegs of the MT roadracer. To maintain the widely used 1 down 5 up pattern a different shift linkage was used behind the engine cover.
MT125Rs used a different cylinder than the CR versions when they were originally produced. At some point the part numbers were superseded by part numbers shared by both the MT125R and the CR125m Elsinore models.
Owners in search of parts after production stopped often substituted complete CR125M motors for their MT125R motors. The first clue is a reversed shift pattern from a stock MT125R (1 up 5 down).
Dyno test of Honda MT125 R-3
HP
torque (lb/ft)
(6th gear)
(6th gear)
HP
torque (lb/ft)
As with any 125 cc roadracer, it was best suited for smaller riders. After bump starting the engine a good start required patience and finesse. To characterize the personality of the 125 cc two-stroke look at the RSC factory tachometer. It did not move or display engine rpm until 5,000 rpm and registered up to 14,000 rpm. With the tall gearing needed for top speed performance it would not pull its own weight until the tachometer was showing at least 9,000 rpm. The engine was in its peak powerband or, "on the pipe" from just below 10,000 rpm and went out of the powerband a little past 11,000 (depending on jetting and modifications).
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Wikipedia