glider wrote:
Could be anything from a bad motor mount.
Ya' know, the more and more I thought about your suggestion the better I felt about your advice. This has happened before.
In 1973 MoCo had all of the Sportsters called back to their dealers and had two support straps welded into their frames. It has been learned that the rear motor mount was cracking. I was your average garden-variety wrench, set-up boy and wage slave at that dealership, and the head mechanic told me it was common to pull a Sportster motor down during that era and already find the rear mount cracked. My Sportster was part of that recall.
MoCo now hydro-forms some parts of frames. Improvement? But let's be honest, a V-twin shakes, and where there is vibration there is stress and metal fatigue. You're right, the mounts should be checked.