Re: How to make a spark testor?
SoLittle - <br />I made one recently out of a piece of 1x4 pine, a piece of aluminum strap, and some sheetrock screws. I used a hole saw to cut a line of 1.5 inch diameter holes (one for each cylinder) along the edge of the board. Position the hole saw so that the hole it cuts will extend beyond the edge of the board. You'll end up with a board with a row of "C" shaped holes along one edge. Leave at least an inch of edge margin beyond the "C" holes at each end. <br /><br />Cut the length of the aluminum strap at least a foot longer than the board. Bend a wide hook shape in one end of the strap. This allows you to hang it on the motor while using it. Attach the aluminum strap to the edge of the board, closing off the open end of the "C" shaped holes. Use small screws to attach the alumimun strap and keep the screws at least an inch away from the edges of the "C" holes. Otherwise, your spark will jump through the wood to get at the screw, rather than taking the longer path down to the aluminum strap.<br /><br />Get some long sheet rock or deck screws. File or grind the diameter of the heads down a little so that they will fit snugly into your spark plug wire caps. Screw them into the edge of the board so that the tip of each screw extends down into the middle of a "C" shaped hole. By turning the screws in or out, you can adjust the gap between the screw tip and the aluminum strap across which the spark will jump. My motor required a 7/16 inch gap. <br /><br />To use the tool, remove the plugs, hook your plug wires onto the tops of the screws, hang the hook off a metal part of the engine, and run the starter.
