Hello R3 Cairns and welcome from Virginia. Triumph doesn't allow me to have a Tach on my Touring so I am useless to your needs there. If there is anything I can do to make you life tougher though, let me know; I'm with the governement and I'm here to help...
I'm with you Boog Mr Triumph and the Hinkley mob never gave me a Taco , so I just pretend I don't want one, I know it will rev to 6250rpm I have the Dyno printout to prove it ,if I rev it to there I reckon I will hear it
G'day and welcome. It is not hard to take the tacho apart (but it is a bit harder putting it back together), so it may be worth checking that it is clean and dry inside. If there is dirts etc in it then the high humidity in your area could cause a few problems.
My tacho has done it as well .. likes been said it has always sorted itself out. R3Cairns there is a long established instrument repairer down in Salisbury , Brisbane . Lionel Otto is the company name , although Lionel has been out of the business for years. Been in the business since the 1960's and has always worked on bikes. Maybe give them a call.
Welcome mate. I've seen a couple of tachos stick from time time. A couple of times (or maybe 3) mine hasn't so much stuck as not returned to zero and then reads higher for a while, depending on how high up it was stuck. Each time it's fixed itself after being turned off for a couple of hours or overnight.