Crispy! Honda cbr900 Reg/Rec failure

MatteH Oxford

MatteH Oxford

MatteH Oxford

Associate
Joined
26 Jul 2010
Posts
1,721
Location
Wiltshire
This happened a while ago, I found the picture on my old phone yesterday so I thought I'd make a thread about it.

My project Fireblade (RRX) decided to stop charging its battery, so I did a quick check and low & behold the reg/rec is shot and has taken out the stator wiring plugs along with it.

10387462_10152668637437889_4616468963389907917_n.jpg



Believe it or not, this passed an ohm test on the stator wiring at the stator plug! (the two burnt plugs live under the seat behind the battery) It was only when I went to check the output of the stator with a voltmeter set to A/c that a problem manifested itself (less than 60v ac @ 5000rpm).

Just goes to show the importance of testing a live circuit rather than a static ohm test.
 
My zx6r did the same,the wires and connectors melted a little,can also be down to thumbing the starter for long periods
 
Hmmm, I wouldn't be so sure about that as stator output at starter rpm is tiny, It's barely 10v a/c at 1,100RPm. The main casue is a short in the reg/rec causing it to output fully to battery at all times rather than discharging excess through the earth. This is what causes the overheat.

Thumbing the starter would really only strain the starter circuit I would have thought?.
 
i have three wires coming from the reg/rectifier to the stator i think

and all three plastic block connectors were melted along with the wires,i don't know how much power it draws,but that happened after i tried to get the bike started after a long lay up,reg/rectifier still works fine

it tells you aswell in the manual not to thumb the starter for long periods and to let it rest in between
 
I pre-empted the failure of the reg/rec on my Fireblade by fitting a MOSFET unit and new high current connectors. The puny original item is resting on the subframe above the new one.

WP_20140526_004_zpsb14fe5a1.jpg
 
The later, revised reg/recs with the cooling fins are much better, though not as good as a mosfet.
The most important thing is to bypass the original routes for the +/- and wire directly back to the battery with a decent gauge wire, which it look like you've done - neat job btw :)
 
You must log in or register to reply here.
Back
Top Bottom