The other day when I started to strip GTR serial number 9730 I realized that I had given the wrong motor and frame numbers for it in another thread. Those numbers actually belong to GTR number 9663 and are frame number 9890 and I gave the motor number as 9920 and it is actually 9950. The two bikes were parked next to each other in a less well lit area of the shop (let's blame that) and I took the numbers off of the wrong one.
The numbers for 9730 are a little funny. The frame number is 9957, which although it's quite a gap, is reasonable. The motor is a different story. It is 8004. I immediately thought that the previous owner, who is also the original owner, had at some time swapped motors. I called him up and he said that while they did rebuild it, that is indeed the original motor.
He bought the bike new off the showroom floor in 1971 and it remained in his possession until 1999 when I bought it. So we are the only two owners of this machine. I know this man to be as straightforward and honest as they come. He would have no reason to be untruthful about this, but it makes no sense to me. Any theories out there?