Hello steamwally , I have reversed the rotation of a Berling four cylinder mag with this help . First rotated the cam ring almost 90 degrees and it changed from clock to anti clock which is what I require but that meant the cam ring arm was pointing down . so had the choice of removing the arm and brazing ? etc on at the correct position but what I did in the end was to turn the points plate about the same degree and leave the cam ring in correct position . I had to file the keyway off the male taper to allow this and just hope it doesn't slip in usage !! It works well 'on the bench' by power drill in all degrees of advance and retard . Thanks , Ken
i fitted a stihl points type ignition plate in an old echo saw... got NO SPARK until turning in wrong direction and then big blue spark.....checked position of strongest magnet and cut a keyway to get magnet leaving 2nd armature end as points open.... now sparks but weaker. strange as the stihl was anticlockwise rotation and echo is anticlockwise rotation....
Hi Kev, you'l need to pull the cam from the rotor shaft. It's a while since I've had one of those in bits but the cam will be keyed in some way and being hardened, they are easily damaged during removal. You will need to remove the key/ locating peg in order to move the cam. Turn the magneto in the desired rotation until you feel the pull of the magnets. The basic (very!) principle is that the spark occurs as the magnetic field is collapsing so with that in mind, set the cam to open the contact breaker at the point you just turned the magneto rotor to- that will get you in the right area, then fine tune as required . To be perfectly honest, there are so many Lucas RS1's still about that if it was me, I would just find one of the rotation required. There is a little more to reversing mags than this video - many have handed contact breaker sets so that the heel of the moving contact bears on the correct side of the cam relative to rotation, so you need to consider the suitability of the particular magneto if you intend to reverse it.
