I read carefully the topic from the experts : Duane, Snowbum and Peter Ardron. Thanks much to them for their help. Duane's method is a good idea but it needs improvement. Peter is right when saying that hammering the rotor can do disasters.
I added 2 ideas to the global scheme :
- The straightening should not be made in the dual lobe plane of the advance plate but in the plane it is actually distorted which could be different.
- The rotor and the camshaft should be straightened separately.
I measured the rotor in a lathe with a dial gauge : it was bent : 28/100 mm. See measurement setup. First of all, I bought a second used rotor. Also bent, but at least, I can destroy one.
Why are they bent ? My hypothesis is that someone, not making the simple tool to extract the rotor did it the hard way. A side-way whack on the rotor or worse on the shaft end. This method is still a common (wrong) method for removing the fan of a 2CV :
So measurement, a piece of chalk and drill press on the right place and I eventually got less than 1/100 mm at the end of the shaft. 5 steps and low pressure on the press each time : 400 to 800 kg. Notice the zinc sheets between rotor shaft and steel blocks. Back to the engine now : no or little improvement. I must admit that the camshaft tip is also bent.
Difficult to measure but when amplified with the length of the rotor shaft, now straightened, it shows 5/100.
The forward end of the camshaft that protrudes beyond the bearing has a smaller diameter and is hollow. This part is weak and it is probable that the inner part is not bent and won't be bent by the following straightening process.
So out the stator, keeping only the rotor with the dial gauge fixed on the engine stud.
I kept the rotor centre bolt tightened with a washer to protect the shaft end. No centrifugal unit for the moment.
With a 2 mm thick flat iron, it is possible to hammer the larger shank of the rotor shaft between the engine block and the rotor rear flange. This corresponds roughly to the camshaft end. This way, no risk to bend the rotor shaft. 2 or three light hammer blows on the flat iron with measurements between. and I got 2/100 mm at the shaft end. I said light hammering: this part is very weak !
I then installed the advance plate and did the measurement on the lobes. A last hammer blow on the flat iron and I eventually got 0 run-out. Now everything is fitted and there is less than 1 mm on the flywheel. Yeah, got it!
Sorry for the European units but after all, these bikes are German!
When positioning the rotor into the chuck, I avoided the small grove of the advance plate.
Are you calling the flywheel, the large diameter of the rotor?
These are the adjustments that promise to allow your bike to run the way it was designed to run.
R69s - R60/2 - R67/2 - R51/3