Total Motorcycle Community Forums

OK i'm new to this internet forum thing so forgive any obvious mistakes
Here's my question.. the rectifier on my '71 yamaha R5 350 is gone and i'm told it'll cost loads to get a new one for an R5...(if i can get one!) Does anybody know of any short-cuts there are to get around the problem? - OR if a rectifier from another bike (eg. RD 350 or YDS7) will make a suitable replacement?

Try asking these guys, they should be able to help you out:
RD Owners.

It'll cost big bucks to get a NEW rectifier for sure, but if there are any motorcycle wrecking yards in your area you can pick up a used one for much less. No guarantee it will work, though.

I recently replaced a rectifier on a '74 cb360 and it worked out fine - $30 from a junk yard - I don't know your bike though - this guy might be able to help, I've read of several people who bought his aftermarket rectifiers and they love them.

http://www.oregonmotorcycleparts.com/

Rectifiers should be mostly interchangeable across most bikes. The only thing that could possibly be incompatible is the current rating and the mounts. Actually, given the compactness of modern silicon components, you can pretty much plug in any rectifier and it should work.

I read a post recently about a guy using a 30-40amp rectifier from radioshack. Before you replace it make sure how many diodes it has (On a yamaha this could be the number of white wires coming out of your rectifier) Normally they should have three diode rectifiers, then you can find a suitable replacement.

Alternatively, if youd like to spend a few more bucks, there's website that guarantees their electrical parts. I'll look it up and post back... in the mean time if this rings a bell in someone else's mind please post.

Gee, i didn't expect so much help so soon. Thank you very much everyone! This website is cool!!
I'll have a look at the RD owners page for sure. I've already started to ring around wrecking yards in Australia and found one guy in another state who reckons he might have something but won't guarantee it's working condition...
I'm still ringing around. It seems to me that R5 parts are hard to come by down here. Most wreckers deal in more modern bike, or dirt bikes.
It's a real pain because my little yammy is my everyday bike. She ran great, that is, until now - still she's over 30 years old I guess. I'm keeping her though.
I'll get back to you all when i get a result.
Thanks again everyone.

http://www.bent-bike.com/

You can check these guys too - I think they ship overseas. They have buckets of used rectifiers for $30US. The search function on their site stinks - if you use them, just email what you are looking for.

Well, it seems that my problem has been solved, and i'd like to say thanks very much to those of you who responded to my request for help.
After much searching on the web and in the phone book, i was flickling thru the back pages classified ads in a local bike mag and found a possible solution. I rang the guy up, he runs a wrecking service from his home, and he proved quite knowledgable about all things yamaha (mostly old stuff, which suits me fine) he said he had a rectifier and could guarantee that it worked. So i had him C.O.D. it to me and now it's in the hands of my mechanic. I know i should prob'ly fit it myself but i'm not that advanced in knowledge or skills (maybe one day, eh?) Hopefully i'll be back on the road in a couple of days. Anyway, i'm just stoked to know that there's so much support and interest online for people like me to access. Thanks again.

Nope it ain't the rectifier coz i replaced and the problem still occured. The battery charges up fine and reads 11.7 volts, but it won't hold the charge for more than 20-30 mins. My suspicion is that the battery is finished, especially if it was receiving 200 volts thru it while the rectifier was not functioning. My local mechanic has been instructed to try another battery and i'm waiting to hear the result. I'll keep yuz posted.

11.7 volts doesn't sound like a fully charges battery to me. Could be the battery is shot.

I've replaced the battery and the problem still happens. The new, fully charged, battery runs down in about 20-30 minutes. The mechanic says the system seems fine (i'm gonna use a diff'rent mechanic I reckon). Somebody has suggested that the alternator may not be putting out enough voltage/current to charge the battery. Is this a big fix?, or cheaper to replace? Any thoughts welcome.
Shall report again.