1975 Chevy Nova

Why does the spark plugs foul out every couple of months?

Engine? Miles? How many plugs foul?

What do they foul with? Black stuff? White stuff? Grey stuff?

This may help.

http://www.aa1car.com/library/sprkplg2.htm

Click on the “Reading Spark Plugs” picture.

Ed B.

Still have the points and condenser???

If you do it might be worth upgrading to a electronic ignition setup.

There are many reasons for fouling plugs…Look at the chart in the link provided. It’ll help.