1969 Yamaha R3 'Grand Prix' 350cc twin
My first riding experiences were in the mid 1960s on a BSA 650cc Lightning that was owned by a friend. He taught me the essentials of riding and the bass-ackward controls used on the Brit bikes of the day. After I got out of the Army in 1968 I borrowed a Honda 305cc from a friend and proceeded to thrash it thoroughly. I rode that little Honda 305 everywhere for several months. Finally, I decided to get my own bike, besides John took his Honda back, and I bought a new Riverside (Binelli) 350cc single from Montgomery Wards. It was the most miserable bike I could imagine. I took it back and got a complete refund within a month.
A classmate from high school let me ride his Yamaha 180cc twin. I liked it enough to go to the local dealer and buy a new 1969 green Yamaha R3 350cc twin. It was scary fast and handled better that most of its contemporaries. The 2-stroke design was easy to take apart. I spent hours tearing it down and tweaking the engine and chassis. I ported and polished the intake and exhaust ports and experimented with the timing. I ended up with a bike that did the quarter mile in 14.0 seconds flat with a terminal speed of ~100mph at the local dragstrip. A nasty spill on it in 1970 resulted in a big dent in the tank. I decided to paint the entire bike black after I fixed the tank. Sadly, I had to sell it to get the money for my 1972 650cc XS2. Here is a few pics of my old 350cc twin. The prints are dated Feb 1971, but the film was probably in the camera for quite a while.
Riverside (Binelli) 350 
1969 R3 - Mint Green
My R3 
The Wild One
1969 R3 painted black I was in my early 20s when this was taken
A winter ride 
My favorite things
Ginger, the R3 and my '66 Impala SS
Yahoo 
Paul's R5
Pulling a wheelie in front of my house Wrenching on a R5 350cc twin