550 onto 650???

[hairygit]

Hi  there, here's a real poser for you all. Does anybody know if it is possible to fit the iron rotor and charging coils from a CB500/550 four to the engine on a CB650 Nighthawk (SOHC) As the main engine castings seem fairly similar, I figure it would be a vast improvement to the charging reliability of my good lady's Nighthawk . Have had no end of problems with the charging on it, whereas I have NEVER had problems with the older types (without brushes) I know there may be some degree of re wiring necessary, just need to know if the rotor will fit the crank, and the outer casing fit the crankcases. Any suggestions/ideas welcome( NOT suggesting putting a match to it, she loves it for some strange reason! )

[Bryanj]

Only way to find out is try it but the wiring moding would be quite drastic

[hairygit]

The re wiring doesn't faze me, I just want to know if the rotor/casing from a 500/550four will physically fit (I'm not into wasting money on her nighthawk when I could be spending it on my bike! ) So if anyone knows, I'd love to hear from you

[andy120t]

Crankcases are the same- my 650 slotted straight into a 550 frame. The 650 points cover fits the same holes as the 550 - but the cover itself is deeper  - so you might find something similar at the other end of the crank (ie) same mounting holes but possibly the 650 one is wider / more heavy duty.