Help What do i got???

[uponone99]

Hello, i just picked up a bike, guy i bought it from said it was a 1974 xs650.... So heres the s/n on the neck 447-007163 and now the s/n of motor s650-127175... I have a feeling this is not the correct year of motor for frame, but thats all the numbers i can find... Also want to know if the Big Bore 750cc Cylinder and piston kit made for the XS650 Yamaha 1974-84 447 Type Engines will work.... thanks... chris

 

[hmusket]

The serial number on the engine indicates it came from a '72, XS2, while the frame is a '74. Here's a link to the model ID thread in the tech section. http://www.xs650.com/forum/showthread.php?t=42
The '72 is a 256 type engine, with different rods, pins, and camshaft. I guess to be on the safe side, before ordering any parts you would have to make sure what is inside the engine, who knows what mixing and matching went on.