Charging system

[Bbarnellb]

I know my stator is shot, but what about the rotor on there should I replace that too? Also could that cause a coil not to get enough voltage to discharge to spark plugs on this bike I know it does on fuel injection?

[Folsoml]

What are the ohms reading across the slip rings? These bikes can get expensive enough without changing perfectly good parts.

[my79650]

Folsoml is right, check the rotor, set your multimeter to the 200 ohm setting and check the rings. Between 4-10 ohms is good, below that is toasted. When the rotor craps out it'll kill your regulator/rectifier box. I just replaced my rotor and my regulator settled at 14.70 volts@4000 rpm, but mine got hot enough to burn my finger. when they get that hot they won't last long. Pinhead has thread on upgrading the charging system, just search it here or on the SOHC site.

[Volker_P]

The stator data is 0.4-0.5 Ohms which is a quite low value.
Multimeters are not very good at that ranges. Typically the stator is all right if it shows a low, symmetric reading between all three yelllow wires.

Typically the stator hardly fails unless it gets hot/molten by rubbing by the rotor.
So I agree that verifying the rotor is a very good hint.

[SchoolDaGeek]

The rotors are the most common failure of the charging system because they are only held together by epoxy and are subjected to extreme heat and movement.

I have had to purchase one each in the last year for my 79 and 81 respectively, they were both bad after 32-34 years in service.

I used customrewind.com for both, $100 shipped with you sending in your own core. You will need a 18x50 bolt to remove it.

Get a "known good" R/R off of Ebay to pair with the new rotor. You can search by cb650, or cb750, or Shindegen SH236-12A