I bought one from Discount Auto or Autozone, I can't remember which, for $6. It just clips onto a ground and has a single connector for the spark plug wire. Works fine.<br /><br />Scott
You can make one (or many) spark checkers by using a regular sparkplug and breaking the ground electrode off. Then take a piece of wire with an alligator clip on one end and strip about 1/2" of insulation off the other. Use a small hose clamp around the plug threads to hold the bare section of wire. Now put the plug wire on the sparkplug and the alligator clip to a ground on the motor. Now crank the engine and the spark should jump the gap from the threads to the center electrode. It is easier than holding a plug against the block and possibly getting shocked.
