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**earlfor** · 08-21-2005, 10:20 PM

Re: would a bad battery be causing a poor voltage?

remove the battery and put it on a battery charger at 2 amps for 8 hours.
Battery voltage on the bench, charger disconnected from battery should be 13+ volts. Let the battery sit on the bench for 8-10 hours. Check the battery voltage again. If it has dropped to less than 12.8, the battery isnt holding a charge and should be replaced. A really good battery will hold 12.9+ for that amount of time after being charged. If your battery only comes up to 12.5, it is due for the trash. 12.5v is only about a 40% charge level.

Even if the battery is faulty, the R/R should charge at a rate of 14.5 volts minimum at 5K rpm. A charge rate of 13.4 is a faulty R/R, so I would say the the junkyard R/R replacement is not working.

The bike will almost maintain voltage level in the system on two working stator legs if the headlight is not used. This tells me one leg of the stator rectified by the R/R is faulty. Stator AC outputs are fine, you have a bad R/R.

Earl

Originally posted by eric?

Recently had the ignitor blow on my 82 GS450L, from what appeared to be a bad R/R sending out too much voltage (shutdown was accompanied by blown headlight and tail light). Replaced the ignitor and R/R with junkyard units. Since then I've been having issues with keeping the battery charged.

Seems like if I leave the headlight off (haven't yet replaced it, so the high/low switch is like an on/off switch now), the battery does OK. If I turn the headlight on, a 20 mile ride will kill the battery. Stator is putting out good voltage (80, 80, and 90 VAC, IIRC. They were all at or above 80VAC, and I seem to remember one leg being 10volts higher than the other two). Battery voltage when sitting is about 12.5, and goes up to about 13.4 at 5000RPMS.

I had the battery tested at the auto parts store, but the guy didn't know what to put in for the CCA rating, so he guessed at 200. Came back as bad battery. The battery was fine before the ignitor failure. I've eliminated most charging system connectors on the bike, didn't seem to help.

What I'm wondering before I plunk down the coin for a new battery is whether a bad battery could be at fault for the charging system not coming up to proper voltage, or perhaps I got a bad R/R from the junkyard?

**Anonymous** · 08-21-2005, 10:44 PM

aside from having to push start the bike now, would I be hurting anything else by riding it like this? I'm more or less dependant on it to get me to work 7 days a week, and the schedule doesn't leave much for getting to the junkyard to get another unit. My only other choice is a truck minus current plates that leaks trans fluid like a sieve :-P If it just means the battery doesn't charge, I've got no problems with push starting the bike for a week or so until I can pick up another unit off eBay and have it shipped out.

**earlfor** · 08-21-2005, 11:03 PM

The problem with used R/R's on ebay is not one seller in a hundred knows the voltage levels it should put out or bothers to check one. I suspect for every 20 R/R's you might buy on ebay, you will probably find only one or two that are not faulty. Its a crap shoot and every one that is faulty/shorted out can result in additional stress on the stator. Faulty R/R's are the number one cause of burned out stators. Used, unchecked R/R's, in my opinion, are not a good choice.

In your situation, I would disconnect the stator from the R/R (unplug it).
Charge the battery and run the bike to work entirely on the battery.
Without the headlight turned on and a battery fully charged to 13 volts, you should safely have about 1 hour of running time. Perhaps a half hour more if operating at slow, uniform speeds and few stops.

As an alternative, the faulty wire yellow lead (AC) on the R/R will usually show signs of melting on the casing, brittle wire, or burned connector. If this evidence is obvious, then you could disconnect only that yellow lead, leaving the two apparently good yellow leads connected. This should reesult in your having 2/3rds of your stator output being rectified correctly and going to charge the battery. Two legs will not charge the battery, but they will come close to maintaining battery voltage if the headlight is turned off. Your run time will be considerably increased. I would still not use the electric starter. The starter will drain a battery in nothing flat.
If your bike starts in the 1st turnover of the engine, I maybe would use the starter, but otherwise, not.

Earl

Originally posted by eric?

aside from having to push start the bike now, would I be hurting anything else by riding it like this? I'm more or less dependant on it to get me to work 7 days a week, and the schedule doesn't leave much for getting to the junkyard to get another unit. My only other choice is a truck minus current plates that leaks trans fluid like a sieve :-P If it just means the battery doesn't charge, I've got no problems with push starting the bike for a week or so until I can pick up another unit off eBay and have it shipped out.

**Anonymous** · 08-21-2005, 11:15 PM

hmmm....I do remember the guy at the used parts place I got this R/R from mentioning that if I cut the plug off, I can't return it (first one he grabbed was the same unit, but different plug...further digging revealed a complete 81 450L in the back lot that I grabbed this unit from). Of course, I clipped the bullet connectors off to solder the wires direct :roll: I know I have some bike harnesses out in the garage somewhere, perhaps I'll cut some connectors off those, reattach to this unit, and see if I can exchange it for another one. I'll just have to take a day off work.

**earlfor** · 08-21-2005, 11:23 PM

When you first get the R/R connected, run the engine to 5K rpm and check DC voltage at the battery terminals. If it is not between 14.2 and 14.9 volts, it is out of spec's and you still have a faulty R/R. Ideally, voltage should be 14.4 to 14.8

Earl

Originally posted by eric?

hmmm....I do remember the guy at the used parts place I got this R/R from mentioning that if I cut the plug off, I can't return it (first one he grabbed was the same unit, but different plug...further digging revealed a complete 81 450L in the back lot that I grabbed this unit from). Of course, I clipped the bullet connectors off to solder the wires direct :roll: I know I have some bike harnesses out in the garage somewhere, perhaps I'll cut some connectors off those, reattach to this unit, and see if I can exchange it for another one. I'll just have to take a day off work.

**SqDancerLynn1** · 08-21-2005, 11:30 PM

First thing to do-- Do NOT Buy a used Suzuki reg!!!! Look for one from a Honda cl/cb 78-82

**earlfor** · 08-21-2005, 11:32 PM

For sure Lynn. That would be about like getting a good deal on used toilet paper. :-)

Earl

Originally posted by SqDancerLynn1

First thing to do-- Do NOT Buy a used Suzuki reg!!!! Look for one from a Honda cl/cb 78-82

**Anonymous** · 08-22-2005, 12:04 AM

Originally posted by SqDancerLynn1

First thing to do-- Do NOT Buy a used Suzuki reg!!!! Look for one from a Honda cl/cb 78-82

My reasons for buying another Suzuki one was that I could plug it in and go. Now that I've clipped the plug ends and soldered them anyways, I'm slapping myself

Any pictures of what I should be looking for, as I have no clue, and these guys are of the type "gotta bring the old one in to compare", which translated means "we have no idea what you're looking for" :roll: