Re: Old Yamaha 175 Endruo Help
I hadn't replied earlier, but if you still haven't got your answer, then list the prefix numbers, and I'll see what I can do. I don't care about the last 3 digits of the serial.
Tweeder's answer from above is certainly a way to get your info. If it has no reed valve, then it is 1969-1971 (CT1-CT1C) if it has a reed valve, but pipe is entirely on right side, then it is a CT2 or CT3 (72-73) If it has pipe above engine but still has twin rear shocks, that would be 1974-76, when the name changed to DT175A to C. After that some time in the late 70s it got a monoshock and a very boxy appearance. i forget when the monoshock model came in, but I believe that it was around 1978-79.
Let us know if you still need help.