I researched the best oil for my Harley and came up with AMSOIL. So yesterday I change my engine oil to 20/50 Syntheic Motorcycle Oil. The noises I'm hearing now scare me to death. I knew it would have a little more noise but this can't be good. If this is how it's going to be I'll have to go back to straight 20/50 HD Oil. Can someone tell me how can this oil be superior in lubrication and let all these parts bang around. Your telling me the banging and clanging is okay? It actually rattles at idle. Anyone experienceed anything similar? I just changed my engine oil on my 2000 Road Glide to Amsoil 20/50 Synthetic. Can't believe the amount of engine noise I have to listen to now. How can an oil profess to being the best lubricant around and create all this banging and clanging? It's got me scared to death somethings going to fall out the bottom. If going back to regular oil stops the noise that's what I'll have to do, I guess. Also does anyone know what the plate right under the crankshaft with a small drain plug in it is? I removed the plug but only got a few ounces of oil out of it. Thanks for your replies.