Motorcycle Repair: 1973 Honda CB125S 12 Volt Conversion, stator rotor, ebay sellers

Question
I have read a previous answer regarding the conversion of the CB125 from 6 to 12 volts written by ThomasL.
See:  http://en.allexperts.com/q/Motorcycle-Repair-837/f/1975-Honda-CB125S-Electrical....

In that answer, he mentions using the stator from a CB200, or CL200, (Part number: 31102-354-005), but I've had difficulty finding one that fits my budget. I have however seen a few CB350 and CL360 stators, (Manufacturer Part number: 31102-286-014) as well as the 1974-77 CB360, CL360 and CJ360, (Manufacturer Part number: 31100-369-004), that "look identical" in the pictures I've seen, (on eBay), and even though the part numbers are different, I was wondering if you could tell me if these other models of stator would work on my 1973 CB125S using my rotor, or not?  Thanks!


Answer
Keith, the stator/rotor on a 6v CB125 is fairly small, so something from a larger twin will probably be too large and/or the rotor won't fit the end of the crankshaft. I suggest that you map out all the dimensions of your current parts and then contact Ebay sellers to see if they can provide some matching parts sizes. The level of magnetism has an effect on the stator output, so just installing a 12v stator doesn't necessarily mean that you are going to get full voltage out of it using a smaller 6v rotor.

Check out some of the Chinese copies of 90-110cc engines, some of which have electric starters, 12v outputs and CDI ignitions.

If you are able to sort out some parts that will work, you will have to find a tiny 12v battery to fit the current battery holder or plan on more mods to make something fit.

After that, you will have to replace the rectifier with something with a voltage regulator in it, plus you will need all new light bulbs. The little sealed beam units from Honda are pretty expensive.

I'm not sure what your vision of the final product looks like, but it seems like you are going to a lot of work on a bike like this. All the early model 100-125s have loose camshaft issues that need careful watching and/or some fancy machine work to install needlebearing conversions to remedy the situation.

Bill Silver