Tachometer troubles

[kman]

So I finally made it to my first track day last weekend and had a blast.  it was raining the whole day so the guys on the supersports couldn't put down any power.  It really leveled the playing field and I was able to make some passes.  I was a little disappointed because I didn't get to drag pegs or anything but thats aside from the point.

Over the last week I have noticed my tach has been a little wonky.  It almost looks like it is coming loose and wiggling, or maybe sticking and then jumping up to where it is supposed to be.  when I accelerate, it gets to around 5 and the hesitates before jumping up to 5500.  It does it again from about 8500 to 9500.  The jump at 5 doesn't bother me but the one that close to the redline is making me nervous since I do not want to get into valve float territory by mistake.  I talked to my local (somewhat) stealership and it may be covered by warranty, but they cannot look at it for at least another week, plus waiting to order whatever parts they need to fix it if necessary.  I am wondering if this truely is something from a manufacturing defect or if I broke it manhandling the revs around during braking and everything at the track.  I did not exceed the redline in any downshifts if that is what you are thinking, although I ran up to is accelerating several times.

The bike is an '08 with almost 8k miles on it and has never had a problem before, and I have ridden in heavy rain before this weekend on several occasions.  I believe it should have a digital tach, which is one reason I want the dealer to check it out since it will probably mean swapping out parts until it is better.  I was also wondering if it could be a loose wire somewhere or something like that as I might have given something a tug unplugging the blinkers/headlight.  It seems to be pretty consistent to be a loose wire but I figure its worth wiggling some connections if anyone has any suggestions.  Has anyone else had any issues like this with the tach?  The guy at the shop was shocked that I had a complaint about the gs

[fongdingo]

have you checked the cable connection on the bike mine has come all the way before it sounds silly but the bike vibrates a lot

[kman]

it does not have a cable the way the speedo has a mechanical cable.  btw my speedo cable came unscrewed just like you describe a few days ago. really caught me off gaurd since I was waiting for the tach to go dead and instead the speedo did. 

[SlimKlim]

What year bike? The older ones have a cable that runs into the front, top of the head and reads off a gear built into the exhaust camshaft. Its pretty slick really when you take it apart and realize how it works. I think the later bikes are electronic, and veypor gauges read some electronic signal, but I dunno which cause Homer installed it. 

[Toogoofy317]

He's got an 08. Mine just went wonky and since it was still in warranty I traded it in and got another one. Be very careful when tightening the screws you can strip them with very little pressure. Don't ask me how I know.

Mary

[black and silver twin]

my 07 has been doing that for the last 8000miles, it only happens at close to full throttle, its so weird.