On the later police KZ's, on the coils, does it matter which post the positive and negative leads are hooked up to? I don't see any symbols or marks to indicate which are which.
For curiosity's sake you could examine the coils to see if they are marked.
The ones on my 81 650 are embossed with (+) & (-). The manual says to connect red to (+) and black & green to (-), but I don't think it really matters, though.
