I own an older Vulcan 1500 Classic 4 speed and alll of a sudden,it does not want to stay in 2nd gear. I found the shift linkage had somehow twisted it´s way out of adjust, and that the locking nuts were all the way in towards the center of the adjust rod. never ran across that on any machine before. Ireadjusted the linkage to speck aprox.3.48 in. with no better results. checked the shift mech. behind the drive hub and the baby seemed to shift ok did tighen the shift hub locking mech. reassemble the bike and same results. I hear that this is a common problem with this year and model. and that their was a solution to the problem.without tearing the motor apart. 2nd gear was replaced at 18600 miles,now just a little over 60,000 miles any advise? or other problemscause this week springs for example