Ilovemountains
XS400 Enthusiast
I just got home from a road trip, I went to pick up an engine, carbs and a few boxes of miscellaneous parts from a guy that I won on Ebay. The bike he was parting was a 1978. Does anyone know why Yamaha changed the cylinder and head shape from the 1977 model? My 77’s top end is square, where as the 78 that I picked up today is much more rounded from the fins to the shape of the head. Any ideas? Any known interchangeability issues?