The CBX charging system has been criticized for having brushes that need regular replacement, for the mere-styling-feature onboard voltmeter, for eventual bearing failure, and for the system’s reputation for sudden electromagnet rotor death. And that’s not counting the self-destructing drive coupler, a problem based on a documented defect in manufacture. However, replacement brushes are available (even the factory’s). The defectively manufactured coupling is easy to fix and even easier to completely eliminate. There is a Denso replacement alternator available, but the original alternator is fashioned beautifully, it’s all Honda, and it is well-supported by a maintenance knowledge base that is shared with other early 1980s Honda roadbikes. It is easy to disassemble and repair.

Being a modular charging system design, the many wire cables and connectors have to be kept up or performance will degrade, but this upkeep is not difficult. The alternator’s two bearings are easy to replace and they are readily available types. And though the electromagnetic rotor will eventually fail, and the regulator/rectifier sometimes with it, and both are expensive and discontinued, limiting options to less reliable aftermarket substitutes, many have used these substitutes and reg/rect units from other Honda models are adaptable. The alternator-to-engine square-section sealing ring is a unique design, but it is still available from Honda, as is the paper, front-to-back housing gasket.

Electrically speaking (not counting the drive coupling), the electromagnetic rotor is the most common failure. It fails one of two ways. One, its wire winding can open, which will reduce its magnetism. Two, the winding can short, which though it still makes magnetism, also unfortunately becomes a severely high current draw on the system, with the result diverted charge, and due to the short, often a burned out voltage regulator as well. When the stator fails (not very common) it won’t induce current. When the rectifier fails it blocks throughput to the battery. When the voltage regulator fails it blocks battery feed to the magnetic rotor. When the keyswitch fails it also reduces feed to the rotor, again lowering charge. When the brushes wear they lower the voltage to the rotor, reducing magnetism and charge. The same with the field coil connectors. Naturally, the whole system relies on clean, tight connections. And note which side of the system is most vulnerable, the input, DC, side represented by the keyswitch, rotor, brushes, and voltage regulator.

Part 5