Topic: CB650 charging problems

[erckx]

Hi! My 1980 CB650 has been struck by the oh-so-familiar charging problem. I've so far had a lot of help from forums such as this one taking me to the point where I am now, but I've kind of run out of ideas what to do next.

How it stands now: The bike runs for 60-80km (with lights), but when killed, won't start over, the battery will be dead. If I jump start the engine and ride the bike for a while with no lights, the battery start charging. I can then kill the engine, and start it again with the start engine.

I've since replaced the old charging rotor with a new aftermarket one, along with a new rectifier unit. But still with the same result.

The battery reads as follow:
   
1500RPM with lights        12.10 (seems low)
1500RPM without lights   12.60 (seems low)
5000RPM with lights        14.10
5000RPM without lights   14.20

Any thoughts on where too look next?

[erckx]

Thanks for your reply calj. I have not made any changes that would affect the electrical system, except replacing mentioned parts. I am charging the battery as we speak, and will check the voltage the coming week.

Yes that's correct, both the regulator/rectifier and the rotor are from Electrosport Industries.

[erckx]

Yes, made measurements on both the rotor and the regulator/rectifier and none were working properly.

[TwoTired]

The 650 has slip rings and brushes.  What is their condition?

What is the field coil ohms measurement when testing from the connector at the rectifier?

Were the voltage measurements in the o.p., made with a fully charged, known good battery?  Discharged batteries (good ones) change their charge state/voltage slowly.

Yes, made measurements on both the rotor and the regulator/rectifier and none were working properly.

Given you can't fix this yourself, you need someone to check and corroborate your work.  Please post your findings/measurements on the components you have determined "bad".