Hi John, There are usualy 3 posibilties that cause low voltage spark on the E27Ns that I know about. The first one is cracks in the plug lead insulation, especially if they are still in the metal tube going from the magneto. The voltage required to fire a full cylinder of fuel and air is high enough to jump more than 6mm in free air. A spark may look great across a plug gap when it is out of the head, but if it dissapears at 3mm gap it won't run the engine. If you do find that your leads are suspect make sure you use wire core ones and not suppression leads. The second item I have found is that darned orange paint on the distributor cap. Mine was all flakey and was storing moisture under it. I ended up polishing most of it off with car cutting compound and that solved that problem. The cap looks odd black though. This is usualy refered to as a cracked distributor cap, but it more often than not is just a thin track of burnt carbon on the surface of the cap where the spark has been traveling. Polish it out and the problem goes away. The third is simply the insulation in the magneto coil breaking down. This usually gets fairly terminal very quickly so I suspect you may have one of the other problems. As for how to get the HT inside the magneto, I am not too sure about that at the moment, but I do have a dead RF4 magneto that I can pull appart to have a look. I was contemplating the same thing a while ago until I got a modified Bosch magneto back with my fathers old E27N. It's in bits in the back yard and the magneto is the least of it's problems. I am in Melbourne, so if you need to borrow a magneto to test out the old girl, I don't mind a trip to the Yarra Valley. The magneto is getting some work done on the impulse coupling and the advance linkage, my father did never get that right when he got it fitted, but I am sure I can get that hurried up if you need it. Let me know how to contact you if you need it. Regards, Frank.
|