Motorcycle Repair: 1973 honda cb450 k5 rectifier, honda cb450, wiring harnesses

Question
Hi Bill, I noticed when re-installing my electrical components and wiring harnesses that the green wire's insuation on my rectifier is nearly melted completely through along it's length. Seems I've read somewhere (probably on the vjmc forum) that these rectifiers have been a common problem over the years. It consists of a green, red/white, pink, and yellow wires, if that's any help. Would you reccomend a aftermarket modern rect/reg replacement? Or what would be the best solution? This is a refurbishing project not a restoration. Thanks.

Answer
Steve, for the most part the charging system components work well on a stock bike. The original selenium rectifiers can be fragile and die with age, over charging or running a bike with a dead/dying battery. Also the current regulator needs to be working properly.

The new solid-state reg/rectifiers are generally a bit more reliable, if purchased from a known company.

If the little harness ground wire isn't attached to the battery ground cable at the battery, the ground system is unbalanced and may have caused the overheating of the wire. Ground lead inside the main harness ties into the turn signal units and voltage/current regulator. When you open up one leg of it, then the current backs up to the next available ground connection, which overheats the wiring.

Bill Silver