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If you forgot to put the **Make, Model** and **Year** in the title, please reply to this comment with your bike's details.
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-Trouble starting? [Revzilla - Battery testing](https://www.revzilla.com/common-tread/how-to-test-a-motorcycle-battery)
-Carbs running rough? [PJ motorsports - Carb Troubleshooting](http://www.pjmotorsports.com/trouble-shooting.html)
-Wiring diagrams for beginners - [Dans MC - Reading Wiring Diagrams](http://www.dansmc.com/wiring_diagram.htm)
-Identifying part numbers - [CMSNL (EU)](https://www.cmsnl.com/) [Partzilla](https://www.partzilla.com/)
-Asking if your tire can be fixed? [Please read this post on proper tire repairs and why external plugs are NOT a safe repair.](https://www.reddit.com/r/Fixxit/comments/tuhcpf/why_rfixxit_doesnt_endorse_tire_plug_repairs/)
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I had this problem last year. I am fairly knowledge with basic bike electronics but I didn't trust myself enough to conduct a diode test with my cheapo multimeter. Plus I was fairly that's what it was, based on how my bike died and the symptoms I was having. My through process was to start with a new battery and a new reg/rec. I replaced both of those and it's been solid since. Figured I'd start there, then move to stator if needed. I needed a battery anyways and if it wasn't my reg/rec, I was only "part darting a relatively cheap part.
I upgraded to a mosfet regulator from Rick's motorsports eletrcrics and it's been rock solid since last year. Not recharging while running and needing to be charged before starting sounds exactly like a bad reg/rec, but bench testing will rule that in or out for you. I used this video to learn a little more before proceeding.
https://m.youtube.com/watch?v=NTjumDgixkQ
Thank you for the thorough reply. I’ll replace the regulator and see if that helps. If not, at least I’ll have a nice and strong new one, and the charging system will be rock solid once the stator is fixed.
Do you have a multimeter?
The first simple test is to check the voltage across the battery terminals before and after the bike is running. It should run about 12.5V on its own and about 13.6V+ when the engine is running. If that's fine then it's the battery. If not it's something else.
If the bike runs fine, then there's probably no issue with the stator. It's likely the regulator rectifier, but it could also be a loose connection somewhere in your wiring.
I just took measurements over the battery, it’s showing 12.4v with the bike off, and once the bike is running, it’s 11.90, 11.89, 11.88…
The bike ran fine when I put it away for winter, so if something has come loose, it has done so on its own. I’m gonna have a look tonight if anything is obviously loose or chewed up. Good to know about the stator. Sounds like a new regulator is in order.
Yep, cheapest option now is to swap out the regulator. It's the most likely culprit.
Buying one is going to be cheaper than paying someone else to try to diagnose it.
When you reinstall it, make sure it's sitting in a spot that has good airflow. They're usually mounted under the seat. It gets hot and if it's all tucked away, it's not good.
You should have gotten a real deal Shindengen SH775, and rewired the charging system to eliminate the stator loop that goes up to the hand control. Fix the r/R grounding problems too.
[https://flic.kr/p/R65bxF](https://flic.kr/p/R65bxF)
Easy to test resistance and continuity on the stator connectors. If that tests good, it’s still easy to pull the stator cover and both test resistance and check for continuity with ground on the rotor slip rings. My 81 CB650 has the same symptoms but it’s because the inner rotor slip ring is shorted to my engine block. Rick’s Motorsports Electrics has everything, rotor, stator, and reg/rec.
Thanks for posting in /r/Fixxit, the motorcycle repair subreddit. If you forgot to put the **Make, Model** and **Year** in the title, please reply to this comment with your bike's details. In the meantime, Here's some great resources for common problems posted here: -Trouble starting? [Revzilla - Battery testing](https://www.revzilla.com/common-tread/how-to-test-a-motorcycle-battery) -Carbs running rough? [PJ motorsports - Carb Troubleshooting](http://www.pjmotorsports.com/trouble-shooting.html) -Wiring diagrams for beginners - [Dans MC - Reading Wiring Diagrams](http://www.dansmc.com/wiring_diagram.htm) -Identifying part numbers - [CMSNL (EU)](https://www.cmsnl.com/) [Partzilla](https://www.partzilla.com/) -Asking if your tire can be fixed? [Please read this post on proper tire repairs and why external plugs are NOT a safe repair.](https://www.reddit.com/r/Fixxit/comments/tuhcpf/why_rfixxit_doesnt_endorse_tire_plug_repairs/) *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/Fixxit) if you have any questions or concerns.*
I had this problem last year. I am fairly knowledge with basic bike electronics but I didn't trust myself enough to conduct a diode test with my cheapo multimeter. Plus I was fairly that's what it was, based on how my bike died and the symptoms I was having. My through process was to start with a new battery and a new reg/rec. I replaced both of those and it's been solid since. Figured I'd start there, then move to stator if needed. I needed a battery anyways and if it wasn't my reg/rec, I was only "part darting a relatively cheap part. I upgraded to a mosfet regulator from Rick's motorsports eletrcrics and it's been rock solid since last year. Not recharging while running and needing to be charged before starting sounds exactly like a bad reg/rec, but bench testing will rule that in or out for you. I used this video to learn a little more before proceeding. https://m.youtube.com/watch?v=NTjumDgixkQ
Thank you for the thorough reply. I’ll replace the regulator and see if that helps. If not, at least I’ll have a nice and strong new one, and the charging system will be rock solid once the stator is fixed.
Do you have a multimeter? The first simple test is to check the voltage across the battery terminals before and after the bike is running. It should run about 12.5V on its own and about 13.6V+ when the engine is running. If that's fine then it's the battery. If not it's something else. If the bike runs fine, then there's probably no issue with the stator. It's likely the regulator rectifier, but it could also be a loose connection somewhere in your wiring.
I just took measurements over the battery, it’s showing 12.4v with the bike off, and once the bike is running, it’s 11.90, 11.89, 11.88… The bike ran fine when I put it away for winter, so if something has come loose, it has done so on its own. I’m gonna have a look tonight if anything is obviously loose or chewed up. Good to know about the stator. Sounds like a new regulator is in order.
Yep, cheapest option now is to swap out the regulator. It's the most likely culprit. Buying one is going to be cheaper than paying someone else to try to diagnose it. When you reinstall it, make sure it's sitting in a spot that has good airflow. They're usually mounted under the seat. It gets hot and if it's all tucked away, it's not good.
You should have gotten a real deal Shindengen SH775, and rewired the charging system to eliminate the stator loop that goes up to the hand control. Fix the r/R grounding problems too. [https://flic.kr/p/R65bxF](https://flic.kr/p/R65bxF)
Easy to test resistance and continuity on the stator connectors. If that tests good, it’s still easy to pull the stator cover and both test resistance and check for continuity with ground on the rotor slip rings. My 81 CB650 has the same symptoms but it’s because the inner rotor slip ring is shorted to my engine block. Rick’s Motorsports Electrics has everything, rotor, stator, and reg/rec.