The Yamaha IT175 is an enduro motorcycle from Yamaha’s International Trial family. It was derived from the YZ motocross bikes but softened for enduro, hare and hounds and trail riding, and it was sold from 1977 to 1983.
Yamaha IT175 at a glance
| Maker | Yamaha Motor Company |
|---|---|
| Class | Enduro motorcycle |
| Family | IT (International Trial) |
| Production | 1977–1983 |
| Engine | air-cooled two-stroke single, reed valve |
| Bore and stroke | 66 × 50 mm |
| Fuel mix | 20:1 petrol and two-stroke oil |
| Gearbox | six-speed |
| Brakes | drums front and rear |
| Starting | kick only |
| Ignition | CDI |
| Tyres | 3.00 × 21 front, 4.10 × 18 rear |
Based on one source (English Wikipedia).
History of the Yamaha IT175
The IT range was built from the YZ competition motocross bikes and adapted for enduro use. The IT175 used an air-cooled two-stroke single running on pre-mixed fuel, with a six-speed gearbox, drum brakes and kick starting. Yamaha made three market versions: one for the United States and Canada, one for Europe and one for the rest of the world. The bikes were designed as enduros and can still be registered today with the necessary tail-light changes or a historical plate.
The IT175D of 1977 used a bored-out 125 cc motocross engine, taking it to 171 cc with the same port design as the YZ. A 34 mm carburettor and reed valve fed the engine, and the six-speed gearbox had a very low first gear for technical sections. The frame came from the YZ with more steering rake for high-speed stability, and the rear used a Kayaba de Carbon monoshock. The rear wheel had a quick-release design and a tool kit was mounted on the rear fender.
The IT175E of 1978 brought minor changes. The 1979 IT175F had a stronger frame, more suspension travel, a slightly different tune for more midrange and reduced fork trail for quicker steering, and it was the last model with the countershaft sprocket on the left. For 1980 the IT175G shared the frame of the YZ125G, moving the shock to a laid-down position, and gained an aluminium box-section swingarm, 36 mm forks with air caps and a new engine with the drive chain on the right. The 1981 IT175H was mostly unchanged apart from white plastics for the United States. The 1982 IT175J had a better exhaust, revised transmission ratios, a return to the 34 mm carburettor and Yamaha’s YEIS boost bottle, and the 1983 IT175K was a minor upgrade. The IT range was superseded by the WR line from 1991.
Design and features
- YZ-derived engine: a reed-valve two-stroke single tuned for enduro rather than motocross.
- Six-speed gearbox: a very low first gear for trials sections and a high sixth for road stretches.
- Monocross rear suspension: Kayaba de Carbon shock, later moved to a laid-down position.
- Practical details: quick-release rear wheel and a tool kit on the rear fender.
Yamaha IT175 versions
- IT175D (1977): the first model, with a bored-out 125 cc engine.
- IT175E (1978): minor changes.
- IT175F (1979): stronger frame, more travel, reduced fork trail.
- IT175G (1980): YZ125G frame, new engine with right-side chain, box-section swingarm.
- IT175H (1981): white plastics for the US market.
- IT175J (1982) and IT175K (1983): revised exhaust, YEIS boost bottle, minor upgrades.
Other Yamaha off-road bikes include the DT125 and the YZ250. More models are in the Yamaha collection.
Sources
- Yamaha IT175, English Wikipedia: family, engines, year-by-year changes, specifications
