Hi ya ! I own a 1994 CBR900 RR which has been down with electrical related problems. The rectifier seemed to give up very frequently. This most often resulted in sudden engine cut-off probably due to poor charging to the battery and with one occasion when the battery blew up under overcharging. My mechanic has been pondering over this problem for months, circuit thoroughly checked but the remedy is usually short-lived. For instance, I have replaced the rectifier three times in a period of 6 months. Can anybody enlighten us on this matter? Thanks !

 

I had a problem with that too when I got my 94' 600 F2 back then. After about 3 years, i changed the rectifier. Still had the same problem. What I did since then, and it is still working now: Purchase a battery tender. Plug this in every night or after every usage before you put it away for the night. This will bring the battery up to par for the next ride. Conclusion: my battery is new, battery tender keeps it up there even if rectifier is going or has gone bad. Give that a try. I heard these R&R's have a bad reputatiion especially on the 900's.

 

I knew this guy with a 93 900 RR and he had the same problems. He had a voltmeter installed on his triple clamp so he knew when the rectifier crapped out and his battery stopped receiving a charge.

 

I'd search the net for it, but I also seem to remeber the CBR900's having flakey rectifiers. This sounds more than just a flakey rectifier though. If you replace it again, feel how warm it is. If it gets uncomfortably HOT to the touch during or after you ride it, something else is wrong. Chances are your stator is kicking out too much juice, and the rectifier overheats. I haven't seen any Honda Motorcycle service manuals, but all the other manuals I have (yam, kawi, zuk) have a section for testing output (entitled something like "Stator (or generator) light (or zero or no) load testing") from your stator and testing your rectifier.

I'd test the incoming voltage and amperage from the stator into the rectifier when the bike is idling, and when your crank it up (to at least 5k rpms) and see how that compares to factory. (or another CBR900 if you can find one)

Stator coils go. They're a wear item.

 

Honda's are notorious for reg/rectifier probs. They run too hot. There was a fix posted on a vfr forum about installing a fan/heatsink combo on the regulator rectifier to reduce the normal operating temperature. It looks like a good idea. I have the link saved at home I believe. I will check later when i get home.

Steven