Topic: '79 cb650 charging issue

[Unexisted]

Hey so I was hoping I could get some advice before I put some money into parts. I'm having a charging issue and it doesn't seem to be the battery although I suppose I can't know right now for certain.

I've done my research and used the electro sport fault finder and everything tested out fine. The rotor came out to 6 ohms which is great. Not too sure if I tested the stator correctly but from what I understood it tested good. Also I've read the stator rarely goes bad. Now the r/r was a little off but tested out. So from what I can guess it's either just the r/r or the battery.

I've cleaned all the contact points I can think of and disconnected my turn signals and left them off. I tested it and it seemed fine when the battery was fully charged(over12-13.5v) so I rode around for about 20 mins then came home and the battery was drained(wouldn't go above 11.7v or so even at 5krpm) so it wasn't just the contact points.

I'm thinking about paying $100 for the aftermarket r/r(and no I don't want to make my own from a '76 ford etc) I'm also going to see how to check the battery although I'm pretty sure it's good. I just don't want to have to buy 2-3r/r's only to find it was something else.

Although right now I'm maybe 65% sure it's the r/r and I'm about to take my chances. My ignition module is leaking that black ooze but I haven't read that that causes any electrical problems. My lights work fine although my blinkers don't blink they just stay solid when used so I disconnected them in an attempt to rule things out.

That's about all the info I can think of right now, I'm just nervous on wasting a $100 or more before I really know what's up? Any ideas or experience with this?

Thanks

[MiGhost]

I've cleaned all the contact points I can think of and disconnected my turn signals and left them off. I tested it and it seemed fine when the battery was fully charged(over12-13.5v) so I rode around for about 20 mins then came home and the battery was drained(wouldn't go above 11.7v or so even at 5krpm) so it wasn't just the contact points.

My ignition module is leaking that black ooze but I haven't read that that causes any electrical problems.

I will start with the ignition modules
The black ooze is the potting compound melting out from getting hot. This is a common effect of charging problems. As long as the modules are still functional they can be cleaned, and refilled with JB Weld.

You can get the battery load tested at any parts store. This would be highly adviseable before replacing any parts.

You did not mention if the voltages are with the engine running, or not. If not checked with the engine running. Charge the battery completely (to enable starting). Check the battery voltage at idle, and approx 2500-3000 rpm. With the engine cold, and hot. Note the differences in the readings.

If the running voltage is significantly lower while the engine is hot. Check the rotor resistance again while the rotor is also hot. This could be a hot short in the rotor.

Another place to check is the resistance through the brushes, and springs. Check them extended, and bottomed out in the holder.

The final place to check would be the harness connector. If this connector is loose, dirty, or corroded. Make sure the connection is clean, and tight.

[Unexisted]

Thanks for the help. I have a friend who used to be an electrical engineer and he works on bikes, so I took it to him. (By the way I did all the tests without the engine running, I'm still learning) but he told me it was the stator.

So for now I'm going to start with that and I'm looking for a stator that will work with my bike. I've found an 82 nighthawk 650 stator and it looks a lot different so I didn't buy it(it was used anyway and I'm trying not to waste money)

So I will probably just replace the ignition modules after the stator. Can someone help me find a new stator that will work? I've found the Electrosport (esg210 I believe was the part number) that will fit if I reroute the oil pressure lead if I remember correctly, as it was for a cb750 or 900.

Anyway I'm sure someone on these forums knows better than I do. Know where I can get a new 79 cb650 stator? I've looked eBay, I just want to be 100% certain I'm getting the right one.

Thanks

[cb650]

a 82 stator is the same but the case was a little diff.   The 83 will be diff.

[MiGhost]

For a rebuilt rotor, and stator you could check out TPE.
Ricks Motorsports also carry the rotor/stator.
Oregon Motorcycle Parts also deal with reg/rec, and wiring harness bits.

[Unexisted]

Cool so I found a new stator on eBay for an 82 cb650 nighthawk that fits MFE 32210-426-005 you just have to sodor a new connector and extend the oil pressure leads. I think the rotor is good but I'm thinking about just replacing the whole system. I'll see if the r/r is good after I put in the stator.