Hey ray, guessing its the tach. My 82 and 91 tac weirded out a couple times. Had the cables replaced, end of problem. Try pulling the tac cable off at the tac and putting some oil down it
Good luck and ride safe,
Here is how I did mine, although it wasn't sticking. Disconnected at front wheel, removed from various cable holders, and then suspended the end high above tac with string and oiled it and left it hanging there for a while. Note did not disconnect from tac.