On a chart i have it is an XS650P, and any in any other country the 650P model was a police bike. Do you know if it was? Could that be why the engines didn't have a number stamped on them or have a 3G5 code stamped.
No, there's no evidence that these were police bikes. They had no special brackets fitted, no attachments and no frame mods for equipment or fairings. And none of them appear to have racked up the heavy mileages you'd expect of police bikes. I suspect, in this case, P was just the next letter in some Yamaha clerk's ledger.
XS650 Specials were a popular model in Japan at the time, hence the extra batch made to Jap specs for Japanese dealers - you'll find lots of pics of ordinary Japanese guys riding round on these blue and maroon models if you Google for pics of 3G5 XS650s.
The lack of engine number is a non-issue too. Yamaha manufactured many batches of their various models - from mopeds to monsters - solely for Japanese dealers when demand required it. None of these were given unique engine numbers, because local vehicle regulations simply didn't require them.
Some markets' Yamaha batches didn't even receive
frame numbers in those days: Pakistan for example, Brazil, Taiwan, Hong Kong, Singapore, Colombia, Thailand, Philippines and quite a few other countries that had small manufacturing runs tailored specially for them. Imagine trying to explain one of those to your local vehicle reg authority's imports department
