Yamaha HS1 90 Motorcycle - Street (1970-1971)

The Yamaha HS1 90, produced from 1970 to 1971, was a street-oriented sport bike powered by an 89cc (often rounded to 90cc) two-stroke parallel-twin engine. This engine featured Yamaha's Autolube automatic oil injection system, dual carburetors, and delivered approximately 10.3 horsepower at 8,000 rpm. Both 1970 and 1971 models were equipped with a 5-speed transmission.

While the core 89cc two-stroke parallel-twin engine remained consistent across its production, the 1971 model year saw the introduction of the HS1B. This distinct model was notably available in yellow and featured front and rear turn signals as standard equipment for the first time, distinguishing it from the 1970 HS1 (or HS1 Street 90). These were primarily cosmetic and equipment updates rather than fundamental changes to the engine or chassis platform.

FAQ:

Q: How can I confirm this part fits my Yamaha HS1 90?

A: To ensure perfect compatibility, please use the year and edition selector at the top of this page.

Q: Are there significant differences between the 1970 and 1971 models?

A: The main differences are cosmetic and standard equipment additions for the 1971 HS1B model, such as color options and turn signals. The engine and transmission remained consistent.

Maintenance