When i had an 83 the local shops here told me that was normal for an 1100..The old saying "they all do it". I didn't have it long enough to figure it out. Got rearended and totalled after only having it a few months. Sounds like crap when taking off from a dead stop.. Like it was pinging really bad.
Thanks for all the Comments, I will check the carburetors. The noise is more of a rattle it mainly happens when I first take off, or if the engine is under strain, like going up a hill in high gear. if I give a little more gas when I take off it doesn't rattle.