I installed a $35.00 tach 2 years ago that picks up the signal from the spark plug. You just ground the thing and wrap the hot wire around the plug wire. It's all right, but... I am sure I saw someone on this web site with a real tach. The chrome job with a dial face. I saw some online, but the guy wrote back that the spark plug wire installation will not work, that the tach needs a signal. ??
Anyone have instructions? I didn't find anything in the tech section.