Should I replace functioning regulator/rectifier?

[bwringer]

This is a bit of a philisophical question. I'm not having a problem, but I want to know The Right Path.

I have a 1983 GS850GD. It's wearing the stock reg/rect, and years ago I added an extra ground wire running directly to battery.

There are no problems, and no adverse symptoms at all. The battery is a couple of months old, but the old battery sitting on my workbench on a Battery Tender is four years old and still in excellent shape. The bike obviously is taking good care of its battery!

But...

I have here in my trembling hands a regulator/rectifier from a Honda CM400, reportedly a fine replacement for the suspect Suzuki part. (I even have my wife's CM400, which I used to verify the way the wiring should go. And explains why I was haunting eBay and tumbled across the reg/rect for $12 shipped.)

The stator tests fine -- 70 - 80 volts AC at 5,000 rpm, as is right and proper. (The connections from the stator to the wiring harness are already soldered.)

Key off, battery voltage reads 12.7 on my digital meter. Bike running, it reads 12.7 at idle, and promptly jumps to 13.6 volts just off idle and stays there up to and past 5,000 rpm. Honking the horn, using the turn signal, etc. only lead to momentary fluctuations in voltage.

By all indications, everything is working fine.

So my question is this: should I go ahead and replace the stock regulator/rectifier with the Honda part?

Points in its favor include the fact that it's easily twice as big as the Suzuki R/R, which would help it stay cool. Also, the Suzuki R/R gets hot when the bike is running. Not too hot to touch, but definitely very warm. I'm also wondering if 13.6 volts is a mite low -- I've heard 14 volts or more bandied about as the target voltage, although my battery is obviously staying quite healthy.

Opinions?

[earlfor]

Re: Should I replace functioning regulator/rectifier?

I spoke (phone) to Electrex in Ca. a while back about their R/R's, charging voltages, etc. I was told the design point charging voltage for an Electrex is 14.7 volts. I think your 13.6 is much too low and I would replace it at that charging level, but asyou say, you have no problems with it and everything seems fine. If you arent having weak battery problems, starting or running problems, maybe just saving your spare R/R until you have to use it might be a good idea. As they say, if it aint broke, dont fix it.

Earl

I'm also wondering if 13.6 volts is a mite low -- I've heard 14 volts or more bandied about as the target voltage, although my battery is obviously staying quite healthy.

Opinions?

[Anonymous]

R/R

79 gs1000, stator, 60 volts ac at 5000 rpm, r/r regulatation,13.2vdc at idle 1200 rpm ,14.7 vdc ( full load)above 2500 rpm and stays there ricks stator 10yrs old and the orginal r/r with an extra ground added witch added a full volt to the whole spectrum, R/R barly gets warm, if its getting hot then your shunting to much current to ground, oh yea and my battery doent boil either

[argonsagas]

The output figure of 14.7 is the high point where the R/R should cut off,
(above that is over-charging) but it is not necessarily the voltage it should pass through to the battery at all times.

It appears the voltages you gave are under normal load on the bike, and you are having no problems of any kind.


As said, "If it ain't broke, don't fix it".

The Honda units do seem to work well...I have one on the GK, mounted because I needed it RIGHT NOW to get home again. Note, please, that it requires a change in the connectors, Your original one will not work with the Honda unit.

[SqDancerLynn1]

13.6 is a little low. Since you have the Honda reg go ahead and install it
& keep the suzuki for a spare

[Anonymous]

I would cast my vote for the ain't-broke-don't fix camp. As my engineer brother is oft to say, "The enemy of good is "better."

[bwringer]

There's one missing piece to the puzzle -- how is the Honda part calibrated?

I think I'll fire up the Honda tonight and see what sort of voltage these things are set to put out.

The poor little thing hardly ever gets to go anywhere. My wife won't ride unless the stars are in alignment, the temperature is between 76 and 79 degrees, there's no wind, there's not too much sun, there aren't too many clouds, it's not too dusty, there's no roadkill that might make her cry...

Since my Suzuki R/R is getting pretty hot, I'm leaning toward replacement. And yes, I know the connectors are quite different, but I've already sorted out what goes where, and I'll solder the connections.

On the Honda R/R, here's the connections:
Three yellow wires ==> hook up to Suzuki stator wires in any order
Red Wire ==> battery + (positive)
Green Wire ==> battery - (negative)
Black wire ==> switched + (positive)

I'll need to run an extra wire to the switched positive, but that's no big deal.

Verrrrry tricky of those Honda engineers. A black wire for a switched positive? I guess they didn't want anyone stealing their parts or something.

[SqDancerLynn1]

I'v had one of those ebay honda reg on my 850 for the last 2+years
they work great! Hooked the switched voltage to the battery side of
the rear brake light
Household wiring the green is ground !

[Anonymous]

I vote with the don't fix what ain't broke group.

[duaneage]

3 years I have had my suzuki 650

3 years it has read 13.9 at normal speeds.

Same battery and I don't even have a "battery tender"
Leave it alone and get a battery volt meter for it. When it gives you trouble, then you'll know.

Low or dead batteries tell the RR to up the voltage. when it is charged the RR backs down to 13.9 or 13.6 abouts. That is what the regulator does, it regulates.

[Anonymous]

The original R/R regulates the output of the stator by either sending the charge current to the battery or the charge current to the frame of the bike. It's called shunt regulation. Either way the stator is working as hard as it can full time. The R/R commonly will lose a diode (since they run hot) and cook a phase of the stator since it's hot from always charging something even if it is the bike frame. The late model R/R does a voltage sense. Either charge the battery or not. Much easier on the stator, and the R/R runs cooler. Best thing I ever did to my bike was to put the late model Honda R/R in. Been 2 years. It's like a new bike. Voltages are better and it tries to charge at lower RPM than the original R/R. It senses the voltage delivered at the load instead of internally (blind). I have also rewound a stator (Not worth the effort). With the original configuration, they get cooked causing the enamel to break down. (Look at them on Ebay, you'll see the top windings (not sitting in oil) are black). The original R/R is a "cheap and dirty" device. The original charging system was the weakest part of my 850. What a difference now.

The original R/R may not be "broke" but it's inefficient and a weak link by design.

schu
1980 GS850

[dpep]

13.6 is a little low. Since you have the Honda reg go ahead and install it
& keep the suzuki for a spare

This is my recommendation as well. Normally I am in the "ain't broke, don't fix it" camp but this I would see a little differently. For one thing you don't know for certain that the Honda R/R you are keeping for a spare works. Install it and if it works, keep the Suzuki one for the spare; you know it works. If the Honda R/R doesn't work, it's better you learned that now.

This is the philosphy I now follow for long road trips. I carry an RR and stator that I know were working when I took them off. It is a lesson I learned the hard way 2500 miles from home.

[bwringer]

I tested the Honda R/R, using the Honda CM400T I happen to have lying around my garage, and it's fine.

On the Honda, voltage stays at 13.9 from idle on up, which is exactly what it should be doing according to the manual (actually, all the manual says is that it should put out between 13 and 15 volts). I don't know why you'd need 14.7 volts, unless you enjoy replacing light bulbs.

The heat buildup in the Suzuki R/R bothers me, and I've noticed that there's little to no variation in the headlight brightness on the Honda when the turn signals flash or at idle. The voltage is pretty much rock-solid no matter what.

On the Suzuki, the headlight dips quite a bit when the turn signals flash at a stoplight and/or the bike is at idle.

The Suzuki's stator output reads 20 - 25 vac at idle (and the normal 70 to 80vac at 5,000 rpm), so shouldn't it be able to keep up a little better than that? I'm hoping the R/R transplant will help a bit with that.

I'll perform surgery tonight and report back...

[AOD]

If it ain't broke...don't fix it!

[Don Lobacz]

I would clean all connectors to and from the charging system first. I would also make sure that you have bypassed the loop in one stator leg that takes it for a little ride up to the light switch. This loop often loses efficiency and makes the others work harder: this could be the source of your "extra" heat.