Motorcycle Repair: charging sytem, bill silver, cb750k

Question
Hello I have a 1979 CB750k it runs well,I have just encountered a problem the charging system the battery brand new started losing its charge,, bike would die we opened up the stator and we found a bad brush one was worn to the line I've installed the new brushes, but the bike is not charging the battery what else might be causing this do you think the stator itself is bad any help would be appreciated

Answer
Thanks for feedback remarks, but I would suggest you find out the actual specifications from Honda before spending money on a stator. Good stator windings generally display very low ohm readings. If the stator windings are not grounded to the stator frame, then it is probably okay, based on the fact that all of your readings are the same for the three phases.

Follow the troubleshooting diagnostic outline at Electrosport, step-by-step and/or call them for assistance, so you don't waste money on the wrong component. Test and confirm, before spending money, needlessly. Call the Honda dealers and ask them to check the shop manual for testing specifications on the stator.

Bill Silver

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Michael, these questions come up a lot with the late SOHC CB650s and all DOHC 750-900-1000-1100cc engine series with this style of charging system.

Often it is the rotor, not the stator that gives issues. Go to www.electrosport.com and check their troubleshooting guide, plus the list of known issues.

If the rec/regulator doesn't appear to be fried, the brushes are good/new and the stator wiring harness connector isn't melted down, then the culprit is usually the rotor. If you need a rotor, be sure to buy the special rotor puller tool to get the old one off the end of the crankshaft.

Bill Silver