Did I told you I recently got myself another bike? It is a "rara avis", a spanish made Sanglas with a Yamaha XS400 engine -Sanglas bought Yamaha engines trying to survive, but failed-. I know it's not a Honda, but the rotor is very similar and I thought you may find this interesting. In any case, please moderators feel free to move this thread wherever you find appropiate.
When I bought the bike it had been sitting for four years. The previous owner told me the starter didn't work before he left the bike sit. He took it to the shop and the estimate was so high he told them to remove everything that could hinder normal working and he would kickstart the bike from then on. Under the seat I found the starter clutch, but the worst part was that the starter motor had the spindle missing!! it was cut, I don't know wether broken or simply cut. Time for ebaying a new one...
Removing the rotor was hard!!! I used the rear wheel axle from my CB350, but I couldn't keep the rotor for turning. When I tried to block it with a screwdriver it snapped broken and almost hit me in the head!!!. A three-prong extractor wouldn't work either. I quit trying and tried again a couple of days later, with new ideas. I used a strap with a knot, going through the rotor slots and then tied to the frame (in the left), and used a heat gun to heat the rotor center for a few minutes. A hard turn of the axle -using another screwdriver and a box wrench to use it as a torque arm- and off the rotor went.
I had already bought a used rotor from the US, but the shipping was too expensive and I told the seller to send it surface. Bottom line, I need to have the bike running before april in order to pass the DMV test so I can make the title transfer. As the other rotor will never make in time, I thought: "why not trying to fix this one? All I need is to make new holes and threads". The old ones seemed to have enough threads left to work, but I didn't want to risk.
No wonder the electric start failed. Seems the bolts gradually loosen and they caused havoc. First of all, use a chisel to remove the raised edges.
Position the clutch in order to mark the new orifices. The idea is to make new orifices far enough from the old ones, but close enough you have space left to go farther in case you fail with the drilling or threading. With a point chisel -is there another name for that?- and a hammer mark the center of the orifices to serve as a guide for the drill bit.
A small bit first to drill a hole that will serve as a guide.
Making the way with the right size bit...
Tapping the holes (M8)
The new hole is threaded...
...and the new bolt turns perfectly!!!
The clutch is in place, the holes were perfectly centered and there is no misalignment -rollers and springs missing, it was just a fit test-
I have the flush bolts and other a bit longer because I thought about using a lock nut, but I don't think there is enough space between the rotor and the primary winding plate.
When I reinstall the set I will use threadlock first and second I will use the chisel to deform the head and tip of the bolts to keep them from easily loosening. I may even use a spring washer in each.
While I was working on it I could'nt help to notice a couple of holes, of different depth, in the side of the rotor. I couldn't understand what where they for, maybe to attach a special tool in them. But then I thought: "the rotor serves also as flywheel. Are they balanced in the factory? Maybe the holes were made to remove some material and balance them. In such a case, the uneven broken old holes and the material removed will have thrown the balance out of the window....
Well, that's all for now. I hope you have find it interesting.
Raul
