Rectifier/Regulator Issue on '83 CB550SC

[Zaxeiler]

Afternoon all,

So, before we even get started with this discussion, I should say, I have no idea what the rectifier/regulator does besides the fact that it has some duty in charging/electrical system.

However, I have been noticing over the past few weeks that I have some liquid leaking from my rectifier/regulator.  It looks clear, and drips from that area (I believe off the fins).  Some of it can be seen on my driveshaft casing, and it drips down off the fins onto the ground.  I'm not sure what the liquid is, as I stated it's clear and I don't believe it's fuel.  It has a hint of fuel smell, but at the very least is diluted with some other liquid because the aroma isn't strong, however, it may just have this smell from the nearby engine.

My question is, is this normal?  It looks like this bike has had this leak since before I owned it (about a month now) because the lower fins on the rectifier/regular are darkened in color.  Is this a typical type of condensation or something, or is this a problem?  And if it is a problem, what would be causing it, and how serious is it?

Thank you for all the input,
Zac

[Adam Roby]

I would say anytime something leaks...  it's probably not "normal".

A rectifier converts from AC (your generator) to DC voltage.  A regulator will regulate the amount of voltage getting to your electronics (~12 volts). 

If this fries you can either go from no power to too much and blow your circuitry, or anything in between.  Definitley a problem to keep an eye on.

[ExTex]

Hi,

550s are nice bikes, but R/Rs do not contain any liquids.  So the leak is coming from somewhere else.
You need to look higher than the R/R and try to identify what the liquid is. ... Brake fluid or engine oil ?
I assume the R/R is located on the left side below the seat, like a 650 ?
If so, then battery acid is another possibility.

None of the possibilities are good.  Check your master cylinders & battery for fluid levels.  That is always a good idea on a new bike.

Another possibility is the drain on the air box.  There is a 3/8" hose that points toward the ground, near the battery vent hose.
This larger hose should be plugged.  Remove the plug and drain out the oil & water mixture.  This is condensate from the air box.
If not drained, it can go almost anywhere.

Let us know what you find.

Ride Safely

 

[Zaxeiler]

I cannot find the leak to save my life...  It's not oil or brake fluid...  If it is anything (pure) it's gasoline, but I still don't know if that's right or not...  I was trying to inspect the lines that run behind the r/r.  Does anyone know what those lines run to/from?

As far as the drainage line from the airbox, it's empty.  And the battery line is connected and doesn't have anything coming from it.

I will continue to investigate, but if anyone has any thoughts, tests to run, or experience with a similar problem please let me know.

Zac

[Adam Roby]

Hmmm..   a regulator requires capacitance to convert from AC to DC.  Capacitor failures may create arcing that vaporizes dielectric fluid.  This fluid is not something I would think could leak, as it is minimal in the circuit - but my knowledge of this field is in household electronics, not so much automotive.

I would suggest keep looking for another source of the fluid, but it can't hurt to measure the voltage out of it.  If you see it is very high, like 18 volts, or your lights seem brighter than normal or are blowing out, cut the engine and look for a replacement before frying your entire electronics system.   

[Zaxeiler]

I still have not located the source of the link.  I thank you so much for everyone's comments etc.  However, the leak isn't constant, so it makes it very hard to find.  I have felt around to some of the fuel and condensation lines behind the r/r, to no avail.  They don't seem loose, wet, anything.  However, every now and again, I notice a drip from behind and off the bottom fins that falls onto the driveshaft...

The power doesn't seem to be irregular or non uniform, when the bike is idling evenly the speedometer and lights are all at a uniform brightness.  The only time there is a fluctuation is during a start, or when a turn signal is on or something of that nature, which I assume is normal/unrelated to this problem since the bike is 27 years old.

Any other guesses would be great, until then, I will keep hunting and searching.

Zac

[Brittles]

Not sure about your 550, but on the 700s one of the bolts that holds the airbox in place is behind the r/r (if I remember correctly). Maybe your airbox is cracked in that area causing your problem.

[chromy]

I pulled a bad R/R apart on my CB650SC just to see how it was put together.  I can assure you there's nothing liquid in it.  All guidance so far has been spot on.  Have you puled the gas tank off to see if it is leaking?  Set it on some cardboard and see if it is seeping due to corrosion???  Otherwise I'm with the others focusing on the crank case vent tank/tube and the airbox.

[Zaxeiler]

It happens so irregularly that I a) don't feel like it's much of an issue (which may or may not be true)...  and b) am having a hard time finding the source.

So thanks for all the suggestions, I'll try and figure it out.  However, I did just post a problem I'm having with the neutral light (and possibly some electrical issue).  So if you get a second, please take a look there, and of course let me know if you think the problem is related to this.

http://nighthawk-forums.com/index.php/topic,4695.0.html

Zac