i have had this bike since it had 400 miles on it. now it reads 48k. for the first 47k miles it ran pretty quiet. about one thousand miles ago, it developed a ticking noise at highway(60-70mph) speeds. this was never present before. vn1500 vulcans have 4 valves per cylinder with an HLA (hydraulic lash adjuster) on each. anyone else ever deal with this?