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Yamaha DT 175

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Make Model

Yamaha DT 175

Year

1979

Engine

Two stroke, single cylinder, reed valve

Capacity

171 cc / 10.43 cu-in
Bore x Stroke 66 x 50 mm
Cooling System Air cooled
Compression Ratio 6.8:1

Induction

Mikuni VM24SS 24mm slide type carburettor

Ignition 

CDI, magneto type
 Starting Kick
Battery 6V, 4Ah

Max Power

16.5 hp / 12.3 kW @ 7000 rpm

Max Torque

8.8 Nm / 12 lb- ft @ 6000rpm
Clutch Wet, multiplate type

Transmission 

5 Speed
Final Drive Chain, DID428SM. 117 links
Primary Reduction Ratio 3.23:1
Final Reduction Ratio 2.37:1
Gear Ratios 1st 33.55, 2nd 20.38, 3rd 14.42, 4th 11.50, 5th 10.09
Gearbox Sprocket 15 teeth
Wheel Sprocket 49 teeth
Frame Welded, tubular, double cradle with single downtube

Front Suspension

Telescopic, oil damped
Front Fork Oil 146cc (4.9fl. oz.) per leg

Rear Suspension

Dual shocks

Front Brakes

Drum

Rear Brakes

Drum

Front Tyre

2.75 -21

Rear Tyre

3.50 -18
Castor Angle 60°
Dimensions Length 2080 mm / 81.9 in
Height  1120 mm / 44.1 in
Wheelbase: 1350 mm / 53.1in
Ground Clearance 265 mm / 10.4 in
Seat height 845 mm / 33.27 in

Dry Weight

99 kg  / 218 lbs

Fuel Capacity 

 7 Litres / 1.5 US gal

The DT-175G was the second last in a long line of enduro motorcycles that can be traced back to the CT-1 of the late 1960's. Its demise in North America came in 1981 due to emmission laws south of the border, but continued and evolved in other parts of the world.

For North America, the 175cc Yamaha series went through four evolutionary phases. The original bike was born in the late 1960's and modeled on the DT-1 250CC, known as the CT-1. These bikes were the first purpose built, dual purpose, motorcycles to come out of Japan, and were very sucessful. They were dirt bikes with enough lighting and instrumentation to make them stree legal. Most of them were stripped of this equipment and used off road. With modifications they were used in all types of off road sport, and were absolutely reliable, right to the end of production.

The original CT-1 was a piston port, two stroke, oil injected, five speed. It came with a low set front fender more akin to a trials bike, and trials tires, most of which got swapped for knobbies. When the model codes changed in 1974, the bike became known as the DT-175. Other changes included engine upgrades including a reed valve, a different fuel tank, a 21" front wheel, thermoflow shocks, and basically a complete restyle, but a subtle one. This model run continued until 1976 and when the 1977 models were introduced, the big changes were revealed. 1977 brought the mono shock rear suspension into the fold, along with a completely restyled bike, a radial cylinder head, redesigned engine, and the whole package was a bit lighter than previous models.

These motorcycles were near indestructable and were among the best to come out of Japan. When our elected officials decided to close the door on these motorcycles, we lost ten fold. In my case, i was in the market for a 175, and one night i saw an add for one, a mono shock version. It was a cold saturday in january when i went for a look. It was a complete, running bike and most importantly, it hadn't been monkeyed with. So, i took it for a drive on the ice, and then bought it. Spring came along with the realization that although it hadn't been fooled with, it also never got maintained so well, and some replacement parts were in order.