I have an '04 XB12S and at 45,000 mi my mechanic told me to listen for clatter that occurred on deceleration that he had noticed on the test drive. By 50,000 mi service the clatter was worse and I had him look for it. He found metal shavings in the oil pan,rocker arm bushings were loose and looked like someone attacked them with an awl,rocker arm shaft was loose which was the cause for the clatter,piston rings had scored the cylinder walls,valve stems were beaten down some, wrist pins and bushings between the piston and connecting rod were looose as well. The bottom line, this engine was blown.I have a 7 yr extended warranty with unlimited mileage and the bike had less than 50,000 mi and was a few days over 3 yrs old.Harley said it was NORMAL WEAR AND TEAR !!!!! and refused to replace my engine.So to all you guys out there with a clatter in your XB motors,remember, the clatter only gets worse!!! Dump that bike as quick as you can because if you don't have an extended warranty you don't have a prayer of getting it replaced.They're saying that 50,000 mi is the life span of this engine and that I should be proud that I personally put all those miles on by myself.Yeh right, I spent over $10,000 on a bike that last less than 50,000 mi.My diagnosis, this bike can't keep itself cool, the oil I mean.The oil broke down under extreme heat and failed to protect the engine.That's not our fault, it's in the design of the engine,air- cooling is not enough.Something broke loose and f***ed up my engine bad.That's exactly why I bought an extended warranty.This is not normal wear and tear.Dump that bike quick, have you ever heard of engine clatter getting better? And somebody pleases find me a lawyer. WORD UP. Angel