Three bad R/R's?

[wolfie]

The story so far... I went with a friend to buy a GS450 as his first bike. It appeared to be in decent shape, and it was a fair price, so I won't complain about the current problems. It had a couple of mechanincal issues, so he left it with me to sort it out. One morning while riding to work, the headlight blew out. I switched to high beam, and it blew it out too. I tested the bike when I got home, and it is running voltage around 15-16. Bad RR per Clymer. No surprise there.

The bike came with some spare parts including a RR, so I tried it. Same result. No surprise there either. Tonight I installed a RR off of a wrecked Honda Nighthawk 650. It check out at 15-16 volts again. Is it coincidence that I picked up another bad RR, or is there another problem that would present like this?

My next step is to try the known good RR off of my 850, but if there is something frying RR's as soon as they are installed, that is a potentially expensive experiment. I've never been particularly good at chasing electrical demons so any help from those more experienced than I is appreciated.

[bwringer]

Did you hook up the sense wire correctly on the Honda R/R? (3 yellow wires to stator - order doesn't matter, green wire to ground, red wire to positive - through fuse, not directly to battery, and black sense wire to any switched +12V circuit.)

Is there already an extra ground wire directly from the negative terminal of the battery to the frame?

Was it a type compatible with the GS stator? Not all Honda R/R are the same type.

If all the above checks out, and the stator checks out correctly (see stator papers), then yes, you need a R/R that's not already broken.

[SPARKSS]

Although it's possible that you've got a bunch of duds, it's less likely. I'll assume there's a battery in the bike and that it's in good condition (not sulphated).....If the battery is open or sulphated and you're pushing or kicking the bike to get it going then you have to correct that first. The regulators used on these bikes (and many small engines) are a shunt type regulator which is basically a circuit that bridges from the power supply to ground and, at a designed voltage level, flows current (an extra load) causing the voltage to be pulled down to an acceptable level. The regulator can not work if it's not connected (or bad connections) OR ISN'T GROUNDED. Likewise the rectifier bridge can't doe it's job correctly if not grounded. On some bikes the regulator and/or rectifier are on a rubber isolated mounting plate and rely on a ground wire to connnect this plate to the main chassis or the battery negative terminal (negative ground system). Make sure this is intact.

Happy troubleshooting

[txironhead]

My brother-in-law's Nighthawk 650 uses what's called a field coil generator, which means that a "normal" three-phase regulator won't work on it because of the two extra wires that activate the FCG. (which means that regulators for his bike are harder to find and much more expensive.) So maybe the Nighthawk regulator isn't the right kind to use on this bike.

Follow the stator papers and get a cheap Ebay regulator off of a CBR600.

[wolfie]

My brother-in-law's Nighthawk 650 uses what's called a field coil generator, which means that a "normal" three-phase regulator won't work on it because of the two extra wires that activate the FCG. (which means that regulators for his bike are harder to find and much more expensive.) So maybe the Nighthawk regulator isn't the right kind to use on this bike.

Follow the stator papers and get a cheap Ebay regulator off of a CBR600.

I'm prone to believe that this is the issue, and that I just have two bad Suzi regs. Odds are pretty decent anyway. I'm going to try installing my known good RR off of my bike, and if that works, I'll order a CBR reg. Thanks for all the help everyone.

[txironhead]

Check the stator via the stator papers before hooking up your good regulator. On the off chance that the stator is frying regulators, you don't want to ruin your good one.