Testing for Spark:
On the last Homelite 5-20 I got, I cleaned the tank, replaced the fuel line and filter in the tank, replaced the diaphragms in the carb, cleaned and reset the pionts, spun her over by hand to check for spark, put her together and tried to start her. NO START. Pull the plug, pull her over and a bright blue spark at .025" plug gap. Primed the carb, pull some more. NO start. Replaced the plug with a new one. No start, but each time she would thorw a bright blue spark with a good snappy sound to it. I became a bit frustrated and figured I would need a new coil. Just for the heck of it (Sh!ts and giggles) I dropped the gap to .015" and the saw fired up. I ran her adjusted the old carb and shut her off to readjust the metering rod. She was running a bit rich. After that fired her up again and readjust the carb again. I ran her enough to warm up the saw and the ignition system to help get rid of any moisture that may have been around or in the coil. After running her and warming her up a few times, I then reset the plug to .025" gap and she hasn't refused to start since. Go figure. Take care. Lewis.