Given the history of the standard R/R, I thought it might be best to just go ahead and replace it now during the "restoration" so that I don't have any problems later. Also, I purchased a brand new replacement battery (Yuasa YTX9-BS) so I don't want to chase around any electrical gremlins. I found one on US E-Bay. The description is below. Anyone use this particular Honda part # R/R? This one in slightly smaller so it doesn't fit on the standard mounting bolts, but there are 4 holes on the sub frame and it fits using one of the other holes. It appears they may have drilled seperate holes at the factory to accomodate different sized R/R's. Thoughts?



"Genuine Honda Regulator / Rectifier
This auction is for (1) Regulator / Rectifier

It is well known that the NC35 / NC30 and many other Honda Regulator / Rectifier's would often burn up.
Honda has done something about it!

Part numbers 31600-KY2-600, 31600-KY2-701, 31600-KY2-702,
31600-KY2-703 and 31600-MV4-000
have now all been replaced by
Honda part number
31600-MV4-010

Now with cooling fins to help prevent overheating!!
Aluminum backing provides even greater heat dissipation!!
Larger internals allow higher output!!

If your motorcycle is on this list then your regulator/rectifier has been
replaced by Honda PN 31600-MV4-010

This regulator/rectifier fits many Honda models, not all are listed

CB - 1 (CB400FM) (NC27)
CB400F,N,2N,2R,2S,3S,2T,2V,3V (NC31)
CB400SF (NC39) (Super Four)
CBR400RR J (NC23)
HORNET (CB600F) (PC34)
CBR600, FN (PC25)
RVF400RR,RT (NC35)
VFR400R3N(NC30)
VT250FN, FN2 (MC25)
VT1000FV,FW,FX,FY (SC36/Firestorm)
VTR250 (MC33)
VT250C ( MC29 )
PC800 R-J , R2J ( RC34 )
NSR250R7L,7N,8L,8N,9L,9N (MC21)
NSR250RR 7L,7N,8L,8N,9L,9N ( MC28 )"

I've just had to change my RR after it fried itself. Mine looked very similar to your picture and I bought it from DavidSilver, they all have fins now. I'll check if I still have the Honda ref around. I noticed the different holes on the subframe too. I thought maybe the previous owner did it but you might be right in saying it's standard. Anyone to confirm, out of curiosity?

Yeah I have one of those on my roadbike.

I still don't trust them as much as the Yamaha units I use.

how do you wire the yamaha reg rec up to the nc30? are the wire colours the same or does it plug straight in?
i have a yamaha reg rec coming from ebay but i cant find any one who can help me with which wire goes where

Too many bad stories with Honda Rectifiers. Just get a 5-wire GSXR rectifier and wire it up. Just match the +/- and the three yellow wires and your good to go.