I've been driving myself nuts the last few days trying to troubleshoot why my generator won't charge the battery when motor is running. I had a separate post about brush re-assembly which I sorted out (thanks m in sc!). I am running a Rick's combo regulator/rectifier that I got from Economy Cycle and I am assuming it is not defective.
So starting with the generator, I checked the resistance between the rotor slip rings and I am getting 4.5 ohms (within tolerance). Then I check the resistance between each of the white wires from the stator and I am getting 1.0 ohms with all combinations of wire pairs. The manual states 0.30 - 0.35 ohms. Looks like my stator is toast but I'd like to hear confirmation from the experts before I proceed.
Many thanks!
stator should have continuity each way but 0 to the casing or ground. i doubt thats it.
This is what my multimeter looks like with bike running. Same behavior if I pull the red lead off the battery so I assume this means nothing coming back from generator?
https://youtube.com/shorts/n8MDySbStxc
I found this post which prompted me to pull out the brushes for another look:
https://www.2strokeworld.net/forum/index.php?topic=5425.msg45925#msg45925
You can see that the brush faces are angled so according to the above post they might be getting stuck i the holders. Thoughts?
vid didn't work.
you should eb able to see the neutral light get brighter if you rev it. it wont charge at idle just fyi.
it might be the brushes. ive seen ones that bad work, but if you plan on keeping the charge system, new brushes would be a good idea.
btw, its an alternator, not a generator.
Try this vid I made it Public:
https://www.youtube.com/shorts/n8MDySbStxc
Multimeter reads the same if I rev it. Neutral light doe not get any brighter with revs.
yup.
def not charging.
worst case, if you need a stator i probably have 5 or 10 of them. lol. you plan on going to deals gap meet next week?
Didn't you also have a challenge with the phenolic washers? Perhaps you have a ground one one of the terminals?
Quote from: AAAltered on April 27, 2025, 06:22:16 PMDidn't you also have a challenge with the phenolic washers? Perhaps you have a ground one one of the terminals?
Yes that was me. I could try joining the green and black terminals that go on the phenolic washer directly to test your idea. Thanks!
Quote from: m in sc on April 27, 2025, 04:41:13 PMworst case, if you need a stator i probably have 5 or 10 of them. lol. you plan on going to deals gap meet next week?
Regrettably I won't be at the Gap next week, but it's good to know you have a few! I'll ping you directly about that. Thanks!
Is there a process on the best way to first remove the brushes,then clean the slip rings so it removes the build-up of carbon that come off the brushes when they wear, w/o removing the alternator assembly ?
remove the whole alternator housing. zip the point bolt off and point cam, easier to clean. you can leave the rotor ont he crank. use some contact cleaner and gently scrub the rings, i use a red scotchbrite, lightly. if you dont have that, wd 40 works to clean, but dry off. rubbing alcohol will work in a pinch, fit new brushes. 0.02
Quote from: m in sc on April 27, 2025, 08:20:54 PMremove the whole alternator housing. zip the point bolt off and point cam, easier to clean. you can leave the rotor ont he crank. use some contact cleaner and gently scrub the rings, i use a red scotchbrite, lightly. if you dont have that, wd 40 works to clean, but dry off. rubbing alcohol will work in a pinch, fit new brushes. 0.02
I remember a person in the past saying 'remove the brushes and use a pencil eraser',but I don't think that will be a good cleaning?
My brushes are both 10mm. Min length is 6mm. Is it an option to try to file the ends off square?
I have filed them before when they got cocked in the holder. Be very gentile, that carbon is pretty soft but yes you can file square.
After you get it back together, hold a small lightweight screwdriver right near the bolt that holds the rotor on, turn the key on and off and you should feel the magnetic pull as the rotor is energized, to prove the regulator is powering it up and the rotor is ok.
Quote from: AAAltered on April 27, 2025, 06:22:16 PMDidn't you also have a challenge with the phenolic washers? Perhaps you have a ground one one of the terminals?
Some progress here! I didn't mess with the brushes but I joined the green and black wire terminals directly together. You can see in the pic the green wire is frayed and may well have been shorting against the brush holder.
So I started the bike and now seeing some different behavior:
- With key on, screwdriver is pulled toward the rotor bolt
- Neutral light brightens up when revved
- If I unplug the red wire from the rectifier to battery the revs go up a little
- Plug red wire back in, revs drop (alternator loaded up?)
- Multi-meter still jumping around when bike running but after revving it up a few times the battery showing 13.2 volts after switching off motor.
- Battery drops to steady 12.5 volts after a minute or so
I think I'm back in business but I'd be grateful for comments on the findings above. Also many thanks to all who chimed in on this, it's been extremely helpful. It also helped me focus on the simple things so I didn't just rush out and buy a complete HPI system (I was having some wallet anxiety over that)
yup. think ypu got it. I'd probably just strip the green wire back and use a connector to join the 2. I'd still get new brushes those are just worn out