Hi everyone.... I'm new to the forum and would first like to say hi.... Reading everyones posts I am impressed by the knowledge here and the way everyone is willing to help. I have a "new to me" 2006 Road king Police with 7,777 miles (Would have been more lucky with that number if I was in Vegas). I purchased it last week from a dealer with no warranty. The bike has a strange problem... In all gears except 5th there is a very distinct and rather loud knock that sounds much like a rod knock. (It is much louder than a standard pre-ignition pinging). However it only shows up at about 2,200 RPM and goes away sharply at about 2,800 RPM. It is only a little quieter when the bike is cold. In 5th it runs in the afflicted RPM range with only an extremely slight knock that would almost seem normal. My first thought was a rod but because there is almost no noise in 5th makes me think twice. Although difficult to tell exactly, it seems to be coming from the front of the engine. The baffle in the muffler for the front cylinder is completely black with carbon and the rear cylinders baffle looks perfectly clean and like new. The bike also seems to be running with no smoke or oil consumption. I would assume that the knock and the soot in the exhaust are related but possibly there are two issues. There is no "check engine" light on. After spending countless hours reading everyones posts I have found a few areas that I am not familiar with that could be causing the problem. However, if anyone has any information or if anyone thinks of anything else, please let me know..... One of my thoughts is that the knock sensing system is not functioning correctly. I don't know if there is a separate knock sensor in this model or if it is derived through a spark plug. (Anyone know?) After reading all of the horror stories about the tensioners failing, is it possible that I am hearing a cam/lifter/valve arrangement that is allowing a valve to either tap on a piston or have such terrible lash that it sounds like a knock? Perhaps it could be a faulty injector or intake air leak causing one cylinder to call for extra fuel which richens the mix for the other? I have not had a chance to pull the plugs yet but hopefully it is simply a fouled plug but I think that is wishful thinking. Is it possible that the transmission has a bad bearing knocking and when it is in 5th/1:1 that all gets quiet because the bad bearing is on the countershaft and then spinning with no load on it? If it is a problem with the tranny the soot in the #1 exhaust would be a separate issue making this a pretty big coincidence. HELP!!!! I'm losing a lot of sleep over this and really want to get it taken care of before this problem creates a catastrophic problem. "Hang on, it's gonna' be a wild ride! Chris."