A few people have written in lately and asked me how to identify an R5. After some searching on the internet, I found that there was suprisingly little information about this. So I've decided to repeat a little information from some earlier posts and other sites to get this info into one comprehensive place.
The Yamaha R5 series is the predecessor to the RD series. The R5 models were built in 1970 (A model), 1971 (B model) and 1972 (C model). The R5 is a piston ported motorcycle, so unlike the RDs there are no reed valves. It also uses a 5-gear transmission, unlike the later 6-gear RDs. It was very similar to the YDS7, and used oil injection and front and rear drum brakes (the later RDs got the front disc brake).
For more information, photos and articles, scroll down the sidebar at left. For official specs, click here or scroll to the very bottom of the page.
In terms of overall model year color schemes, from what I've gathered:
1970 R5(A) - Metallic Purple/white
1971 R5B - Mandarin Orange/white
1972 R5C - Mandarin Orange/black
This is the way you can tell the model years apart visually. But, as so many surviving bikes have swapped/lost body parts or been repainted, the next step is to check numbers:
Engine or Frame Numbers (start-end)
1970 R5(A) - R5-000101 - 013649
1971 R5B - R5-015101 - 042209
1972 R5C - R5-100101 - 130606
The R5 shares the same serial numbers for both engine and frame. You can find the engine numbers stamped in large numerals on a flat section of the left side of the case, above the shift lever. If the flat spot is there, but no number, most likely you have a replacement case.
The frame number is also stamped in large numerals on right side of the neck of the frame, just in front of the tank.
This info comes from a dealer document listing colors, start and ending engine and frame numbers on all Yamahas '62-74. A very generous Don Q scanned the docs from 1970-1972 (R5 model years) and posted them as PDFs on his site. The rest of the pages are so bad they are not readable and Don will have to type them up manually. His files are pretty big because of the scan, but have a great old photocopied look to them. You can download them from his site here, or you can download smaller, slightly cleaner PDFs here:
1970 R5(A) (536k PDF)
1971 R5B (656k PDF)
1972 R5C (756k PDF)
You'll need the free Adobe Reader to view and print the files.
Don is a very talented striper, flamer, letterer and artist located in Costa Mesa, California. There's some really good stuff on his site - check it out! Special thanks to Don for sharing this info.