Back when people were racing those thing in the "Box Stock" class, some would cut the stock pipes apart, build expansion chambers in them, weld em back up, chrome them and cheat away! They weren't the be
That was my first street bike. Same year and color. I had a lot of fun on it for a couple years. Put some Yamalube in the reservoir under the seat, gas it up, and go. Quick and wheelie prone. Sold it and bought a Honda CB750, I could haul the chicks better on the 750.
Out of all the cool bikes down at the Gap this week, the tall Dutch kid riding a 1966 Kreidler 50cc across North America was the neatest thing I saw. He just happened to be in the area during the annual 2 stroke gathering at Deal's Gap.
My first ride was a bone stock 75 Yamaha RD350 that I bought, along with a windshield, rain suit, and a helmet for $600. Rode it around the block for an hour learning how to ride, as I had never ridden a motorcycle before, then took off for home 75 miles away. Great little bike and wheelie machine.
However, I would NOT buy that trouble in the posted photos for half the asking price!