1978 yamaha xs650 chopper motor?

[Dani G]

The XS650 has always been a favourite chopper engine, but if you must have a bigger motor, then the XS650 can be bored and stroked all the way to over 1000cc. That would solve your problem.

 

[Buster Brown]

You ought to be able to find a replacement XS engine easily enough if yours is no good. Why not stick with what the frame was designed for as long as you can get it.

Just about any unit-construction twin should fit, but there aren't a lot of attractive options. A 750 Triumph, Norton or Kawasaki would probably go but would gain you little in the way of horsepower. I'm scratching my head trying to think of parallel twins of 900 or 1000cc, but I come up with nothing. The bore and stroke options for the XS could be a more attractive choice.

 

[kurt]

Last few years i have been working on building a chooper out of a 1978 Yamaha xs650. I hartailed the frame raked out the front end. Since i havent had much time recently due to children i dont know if the motor is good anymore, That had got my mind running about putting a bigger motor on the bike. Does anyone know if there is a bigger motor than a 650 that would fit in a 1978 Yamaha xs650 frame? I do not have a welder but i could get the motor mounts changed.