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The 2-Stroke Garage => Micro Muscle: Under 100cc's => Topic started by: Rizingson on July 10, 2025, 07:50:32 PM

Title: Yamaha's First Rotary Jets
Post by: Rizingson on July 10, 2025, 07:50:32 PM
The Yamaha YG1, first introduced in 1963, was a popular small motorcycle known for its sporty design and practical features. It featured a 73cc single-cylinder, two-stroke engine with a rotary disc valve and a four-speed transmission. The YG1 was praised for its reliability, ease of maintenance, and enjoyable riding experience, making it a successful model for Yamaha. Just like Honda's C100's the little YG1 was Yamaha's bread and butter during the early to mid sixties which kept the company afloat. 

Here's my 1963 and 1964 YG1 Yamaha's. Both are pre-mix models as Autolube wasn't released until August of 1964.
IMG_8059 HDR.jpg

The 1964 is a survivor, I did a partial restoration on the '63 as it had more patina than I liked.
IMG_8061 HDR.jpg

The easiest way to identify the '63 from the '64 is by the tail light. In 1964 the tail light was enlarged from the round '63 to meet new DOT requirements beginning the first of the year in 1964.
IMG_8063.JPG

IMG_8067 HDR.jpg
Title: Re: Yamaha's First Rotary Jets
Post by: RDnuTZ on July 10, 2025, 08:30:18 PM
very cool! 1 of the 1st bikes I rode as a kid was Trailmaster 80 and I can see some of the design ques from yours made it into later products.
Title: Re: Yamaha's First Rotary Jets
Post by: Simmons1 on July 10, 2025, 09:00:14 PM
Very nice old bikes. :whistle:
Title: Re: Yamaha's First Rotary Jets
Post by: m in sc on July 11, 2025, 08:15:59 AM
man those are cool.  :clap: