I recently used & abused my Husqvarna 16" chainsaw, and the chain was pretty dull, but I kept going. After I finished, it was hard starting and tough to idle, and the chain would spin even at idle, and even when the starter rope was just pulled. I finally got the carb adjusted so that it idles & revs OK, but the fix for the spinning chain surprised me. The clutch was OK, and when I took off the sprocket and needle bearing, they were OK, but the chain would turn if I spun the clutch, when the spark plug was out. It turns out that under the sprocket, the sprocket engages the plastic insert, which is the oil pump drive. It is Husqvarna # 544212402. The new one arrived today, and spins freely over the engine crankshaft. The old one would bind against the crankshaft, and so the chain would spin at idle. I'm sure it would not cut wood this way, but it sure could hurt someone if the chain is moving. Wow, maybe the original one warped or something when I overdid it (from debris in there, or maybe excess heat), cutting with a dull chain, because I was too stubborn to stop. Anyway, it's just something to keep in mind, if the chain moves, even when the rope is pulled. And now that the chainsaw is working normally, it let me increase the idle speed a little from where I had it when I was trying to stop the chain from spinning before.
40.1 KB Views: 79
38.1 KB Views: 6