On a ride w/ friends this weekend, the speedo on my 84 shovel (FLH) seemed to suddenly start reading around 10 miles faster than my actual speed. I've check it in the past and it was right on but now it's showing way above my real speed? Help anyone?

 

That is an older model than I am familiar with but I have had to clean my speed sensor a few times. Not the same symptom I have experienced as mine would bounce but something quick and easy to try.