Ignition coil

Hello everyone
I just bought a ignition coil for my 1980 kz 250 and I would really appreciate some help knowing what polarity the wires are. The first wire is yellow and red and it goes directly to the start button and the second wire goes into the engine. The coil has a positive and negative but I don't want to hook up the wires wrong and fry it. Thanks

The yellow and red wire goes to the kill switch (Power + for the ignition)
The second black wire goes to the engine ground (Negative -)

BTW, Hello and welcome to the KZR forum and please introduce you and your bike with some pics.

Thank you so much I'll try it out right now and I'll post a pic of the bike as soon as I have it all back together

Please add your bike's year and exact model to your signature line. Kawasaki made single cylinder and twin cylinder KZ250 & Z250 models, so pinning down the exact model will help us help you. Ed