The General Motors HEIModule (High Energy Ignition) is a very “Powerful” part. The HEI is great “converting” a points engine into a “semi points” engine. I call it converting, but truthfully the points still remain in use. The points normally charge the ignition coil(s), drawing an amp or so through the points. Having a few amps pass through the points a few hundred times a minute has a pretty big toll on the points longevity. Adding a HEI into the ignition takes on the points’ job by charging the ignition coil(s) versus the points having to charge the ignition coil(s), and now the points send a “signal” to the HEI, and the HEI will amplify that signal.
It is important to keep the HEI cool. Mounting the HEI to aluminum works great to transmit heat.
Double check your wiring after installing the HEI! Nobody wants to burn up their work or damage the points or HEI due to a simple mistake!
Just installed the HEI and you are getting no start/spark?
Try checking that 12 volts is going to the B Pin on the HEI module. If not, jump 12 volts to the B Pin to eliminate any wiring issues.
12 Volts is being fed to the HEI, but still no spark is produced at the ignition coil(s)?
Try jumping G Pin directly to a ground, maybe even the negative post of the battery. Often the case will be a bad ground.
Here is an installation of a GM HEI on a Cushman Truckster equipped with a 22hp OMC engine. Wow did it make a difference!
Oh would ya look at that! Another Cushman Truckster with an HEI ignition upgrade!