Description
Yamaha YR3
Yamaha YR3
Museum quality
1969 Model
350cc
UK licenced
Best in the world ?
this is probably the best example of this motorcycle available anywhere. Beautifully restored it presents in immaculate condition.
Model History
Yamaha’s YR3 represents the third and final iteration of the company’s first full-on 350cc sports machine. Back in 1966 it was very evident that Yamaha was rapidly catching a cold when it came to machines over 250cc. Overboring the vertically split engined YDS series was only ever going to be a stopgap measure but for a while it looked like it was Yamaha’s only answer to Honda’s CB77.
Following Suzuki’s launch of the Super Six T20 it was obvious that the way forward was with something similar but bigger. Project YX03 delivered the genuinely new, if slightly quirky, YR1 and the company finally had a fully fledged 350 sports twin. The following year the engine and peripherals were revised to deliver the YR2 and for 1969 rolled out the YR3.
The bike might only be a 350 but both it and its predecessor established the concept of a sport 350 stroker as a giant killer. This was largely due to radical revision of the porting used on the original 1967 YR1.
In place of the initial three port system installed two Z-shaped auxiliary ports at the rear of each cylinder. These cut-outs allied to corresponding windows in the rear of the pistons transformed the engine’s characteristics. The new porting facilitated enhanced gas flow within the motor, delivered a significant boosting effect to the ejection of combustion gases, cooled the pistons’ crowns and cylinder head thereby gaining better efficiencies.
From this point on Yamaha’s 350s were machines to be respected not sneered at. Often forgotten now but in 1969 Yamaha’s UK agent, Mitsui Machinery, didn’t have a machine bigger than the YR3 in its line-up and probably didn’t need one such was the potency of the bike. Certainly Yamaha sales in the UK didn’t suffer because of it. For 1970 Mitsui could have imported the new XS-1 650 four-stroke twin but chose not to and carried on with the new YR5. Proof positive that biggest isn’t always best!
This Machine
Oh well, this is something rather special. Acquired at auction in the USA in 2021 with another Y3 (in red coming soon) the condition of this bike has to be seen to be fully appreciated. It has had a full mechanical and cosmetic restoration, and probably looks better than new. When we got it into our workshop and found some mechanical issues which took a while to resolve (try finding a throttle cable for a Y3 -you cant we had to have one made). The bike was shown at the Classic Motorcycle show at Stratford and received a lot of attention it really is rather beautiful.
