Now I have arrived home I have consulted "Nick Harris" and "Mick Woollett" (TT1907-1989)...Book say "new 4-cylinder 125 in 1964" but no mention of 5-cylinder.. Yet,I also have Sound Stories with Luigi saying "5a-cylinder.."..

Reputed to rev to 16000 with an eight-speed box top speed in excess of 125 mph..

So what's the story folks ?????

Yamaha won the 125 in 1965 but in 1964 Honda won on a "debut" machine-----Surely that was the 5-cylinder ???