Just a thought, put bike on lift, remove front sprocket then let chain hang down in a gallon can full of kerosene. Clean that 18" section then roll the back tire and do the same with the next 18" section of chain. What's that sound like? Never tried it but I remember all the slack when I changed the sprocket.

jerry

2005 America, Green, Thunderbike exhaust LEAD, FOLLOW, OR GET THE HE** OUT OF THE WAY!