Topic: Replacing My Rectifier

[AndrewCola]

Howdy,
I was having power issues and my engine was bogging down hard... also there was backfiring and tears. So I cleaned out the carbs and jets but it all seemed to be good. A friend told me that he had had a similar problem and that it was the rectifier, so I checked out some posts here and decided to get the R255a rectifier from Oregon Motorcycle Parts as recommended (http://www.oregonmotorcycleparts.com/rectifiers3p.html).

It came in today and upon removing the stock rectifier I found that the it had the 5 wires that the new rectifier has... plus 3 more wires coming out of the other side and plugging into something else on the bike. You have no doubt guessed that I am way over my head when it comes to electrics.
So I've included 2 pictures... the first is the old rectifier with 8 wires, 3 unknown wires connected to the bike, and the 2nd is the new rectifiers with just the 5 wire plug.
I'm guessing that the old rectifier is also a regulator? If so, what should I do? Get a new regulator as well?
Thanks for your help.
Best,
Andrew

[77honda]

Looks like the recitifer in the top photo is a combination unit (Rectifier/Regulator)
The one you have purchased is stock replacement and requires a regulator

Original 750K had Regulator & Rectifier.
5 wires from Rectifier and three from Regulator

Recitifier has 5 Wires
3 x Yellow
1 x Red
1 x Green

Regulator has 3 wires
1 x Black
1 x Green
1 x White


Hope this helps.

[CycleRanger]

Lots of info in this thread.

http://forums.sohc4.net/index.php?topic=12465.0

[AndrewCola]

Ok so as I understand it, I'm trying to replace a regulator/rectifier unit with 2 separate units... a regulator and a rectifier. I have the ladder, but as you can see from the picture of the new rectifier, there is only the 5 cables and no place to connect a separate regulator. Any ideas? Any recommendations for what kind of regulator I should get?

[CycleRanger]

Personally, I used this: 
http://www.amazon.com/gp/product/B000C7YK4I/ref=oh_o03_s00_i00_details?tag=vglnk-c1583-20

[Bodi]

A lot of people use the ones here www.oregonmotorcycleparts.com with good results. They have rectifiers, regulators, and reg/rect combined units. You can get a stock electromechanical regulator as well, ebay is a good source and most bike wreckers will have a bin of them, they were used on many 70's Honda bikes.

[AndrewCola]

@Bodi, oregonmotorcycleparts.com is where I purchased my new rectifier. I got the R255a model for 69-78 SOCH 4's.

Good lookin' CycleRanger. I just ordered that reg from amazon. The rectifier that I have seems to be plug and play... but do I need to connect it with the regulator some how? Because there doesn't appear to be any other places to put wires on the R255a rectifier that I have.
Thanks again yall,
-Andrew

ps. I've included some pics of the old set up. 1st one's with the old rec/reg attached and the 2nd one is of it removed where you can sort of see the 3 reg wires (G W B) coming out and hooking into something else in the space time continuum.

[Duke McDukiedook]

If you would have bought a cheapy harbor freight voltmeter it would have been able to tell you if you had a bad rectifier in the first place and you could have potentially saved some money. Pinhead has a good thread on his cheap rectifier replacement if that is all that is wrong in your situation.

[kpier883]

subscribing

[Duanob]

I was going to say while you were on the Oregonmotorcycleparts website, he has probably the best and easiest to follow FAQ on trouble shooting electrical systems for these old bikes. I followed it and was amazed at what the problems acutally were, and they cost only a couple of bucks worth of connectors and blocks and wire and shrink wrap instead of $100 worth of new VR and Rect.

[CycleRanger]

Here's how I mounted my solid-state VR.
You can also see how the VR connects to the harness.

[Spanner 1]

Sure you have been losing power OP, the sh1tty looking fuse set-up needs to be adressed first, before you spend moolah on any new rectifier or regulator.. just saying from experience  : ... hope your new parts fix the problem