The magneto is not very complicated. If the points are clean and have low resistance when closed, they are opening and closing, the wires are continuous and not grounding out anywhere, the flywheel is still magnetized, and the laminated steel core of the coil almost touches the flywheel on both sides of its center, then you have a bad component: condenser or coil.
When you tried a different magneto, do you know the replacement one worked before you removed it? Are you sure it was grounded properly when you installed it? Did it work again when you put it back in the original mower?
There is no witchcraft involved here, the system is rather simple.
Last edited by grumpy; 26/04/10 04:07 AM. Reason: add two more possible problems
