Motorcycle Repair: stator on a 1980 cb650 custom, honda oem parts, regulator rectifiers

Question
hi, i have a 1980 cb650 custom,i have done alot of work to this bike, mostly normal matinance, but i have a problem, i had bought a new battery and rode it for a bout 6 miles and the battery went dead and the bike was acting real funny, like it was misfireing,so i recharged the battery and rode it for a while and its fine until the battery dies,when the battery gets low it acts funny again, i was told this was due to a bad stator, i was wondering if you could point me in the right directions and see if you could guide me through intallation,and how hard would it be to install a stator. thank you for your time and the help will be greatly appreciated. thanks again, Ryan

Answer
Ryan, do not blindly replace a component until it has been tested. Stators are not common failures on these bikes, unless the connector from stator to wiring harness is melted down. Defective stators can occur and can also take down the rectifier-regulator if that happens.

Go here for the pdf troubleshooting file.
http://www.electrosport.com/technical-resources/library/diagnosis/fault-finding-...

I have had numerous questions like this and most turn out to be bad rotors, not the stators. ElectroSport has rotors and stators and regulator rectifiers which are all cheaper and more available than Honda OEM parts. Checking the rotor tracks, cold and hot will usually reveal the issues of defective rotors. You are looking at 4 to 6 ohms resistance between the two tracks.

Note: These bikes have carbon brushes that run on the tracks of the rotors. The brushes wear down... when they quit touching the rotor, the charging system stops functioning.

http://www.bikebandit.com/houseofmotorcycles/honda-motorcycle-cb650-1980/o/m1974 for parts illustrations.

You will have to purchase a special rotor removal tool, if the rotor replacement is necessary.

The stator is mounted inside the outer cover, so it is just a matter of unplugging the wires, removal of the cover and then removing the retaining screws for the stator/cover assembly and reversing the process. Check the brush lengths when you have the cover off. There are usually small warning lines scribed on the brushes, so you know when they are worn down too much.

The ignition system is transistorized and battery operated, like most cars. Dying batteries will cause the electronic circuits to shut down and the bike gets a very weak and erratic spark to the plugs.

Bill Silver