CB400F regulator/rectifier

[MikeSB6]

Hello,

   the seventies CB400F uses a separate rectifier and regulator, according to the wiring diagram. Is it possible to use a modern 12V one piece regulator-rectifier instead, and what wiring changes would be necessary? Any help gratefully received!

    Cheers, MikeJ

[mike the bike]

Yep, it's a recommended fix. 

[MikeSB6]

Hello, thanks for the reply. I notice that some reg/recs have one yellow lead rather than three , so which type would be suitable?

   Cheers, MikeJ

[mike the bike]

Make sure you get a 3 phase reg/rec.  The colour aren't that important.  The 3 ac inputs are yellow on a Honda but other manufacturers differ.

[Gixxer-18]

I've just bought a Reg/Rec  from electrexworld Ltd for my cb350/4 part # RR24 £78:00 inc VAT plus £4.50 p&p fits the 400/4, 500/4 and 550/4 too. Direct fit to the OE wiring loom. [ Guests cannot view attachments ]

[Johnwebley]

I just got the same.for my 500-4,

 unbolt the rectifier,pull out the plastic plug,plug the new unit into the socket,remove the regulator,conect the black and white leads,ignre
the green lead,

 mount the new unit,

and its all done

that easy

 15 mins at the most,

PS,got mine from Wemoto,very prompt service and delivery

[MikeSB6]

Hello,

     many thanks for the info. but is there a standard later Reg/Rec that will fit and cost a bit less?

      Cheers, MikeJ

[Bryanj]

Nope, the later bikes have a brush fed wound rotor

[Dave_Canada]

A DOHC Honda four- say 80's CB750 - has a compatible R/R EXCEPT the field coil connects differently. Find the other field coil wire (not the one to the regulator), it's grounded in the stock system and has to be connected to a black switched power wire for the later system.

[MikeSB6]

Hello,

thanks for the replies, I'll have a ponder

   Cheers, MikeJ

[MikeSB6]

Hello again,

   I've just acquired a used reg/rec from America which was taken off a 1970s CB400F, but it only has the three yellow wires in one plug, with the black/green/red-white leads in a separate plug, but no white wire. Any ideas anyone? The sellers say that the unit was taken from a working bike.

    Cheers, MikeJ

[gtmdriver]

I've just fitted the Electrex World combined unit to my CB350F and electrically it's a direct swap but you have to make up your own mounting system and it's a good bit bigger than the OEM rectifier.



I mounted it by sandwiching the original regulator bracket between a pair of stainless steel straps but if I ever get round to pulling the battery box out I'll make up a proper mounting.