When I experienced shutter issues the bike had been sitting for almost two weeks with no riding. After a couple of rides temp gauge seemed to begin working on its own -- but, as advised I removed seat bowl and "jiggled" any wires I could reach. I did run a dose of "Sea Foam" thru a full tank.
Since these problems popped up I have ridden most every day -- and most days included several outings and some of longer duration.
My report: (hoping not to jinx the situation).
--Shutter has disappeared.
--Temp gauge is working consistently
--"elephant trumpet" noise I've seen mentioned happens less and clears up after it gets well warmed up.
So, I'll look deeper into potential fixes mentioned if it comes back up...but, for now...a couple of folks advised that
it could be suffering from lack of riding...and maybe riding a bit too much like a "douche". My throttle up is a bit more
assertive now and that seems to be helping also.
Thanks all for the tips.