How do you test if a spark is getting to your spark plug?

You can do several things

1) You can touch the spark plug wire while someone turns the engine over; a shock means it is getting juice

2) You can remove the sparkplug wire and let it rest as near the spark plug as possible. Have someone turn the engine over and watch for a spark to jump from wire to plug. Blue = good, yellow = weak.

3) You can remove the spark plug, leave it plugged into the wire, place the plug on solid metal (engine block, intake manifold) then turn the engine over. Watch at the electrode part of the plug; blue spark = good, yellow = bad.

Remember - if you are touching either the plug or the wire when the engine is turned over you are going to get a nice healthy jolt. Not life threatening but not fun either

You've taken the plug out, and reconnected the wire to it? Then you need to ground the metal part of the plug to the motor (a metal part, obviously). Most people lay the plug on the cylinder head. Then get someone to crank it while you watch the spark gap.

The old mechanics test was sticking a screw driver inside one spark plug socket and pointing it to motor or chassis ground and having somebody turning the engine. However this is dangerous if you don't know how to do it correctly because you can get an electrical shock or cause a gas explosion. The way to to do this safely is with a spark plug tester that cost only few bucks. This tool you can buy it in places like Harbor Tools Supply and in some auto parts. Then you will place the testing tool between any of the spark plugs socket and spark plug tip. Now have somebody to turn the engine and the a light signal will show if there's current going to that particular spark plug. good luck...!