Weird issue with speedometer jump

[Mneitzer]

I have a relatively newish MotoBravo Superhornet (yeah, the overpriced one that looks kinda like a crotch rocket). I've been having a blast on it for about a month. the speedometer is off, but it's consistent so I've just adjusted how I read it.

Here's my problem, last weekend, I was taking a ride and noticed that my speedometer said I was going well over 90mph, normally it doesn't break "70". The odometer is spinning, but the speedometer just jumps all over the place. Weird thing is, it just happened after I re-jet the carb (very small change).

My question: Does this sound like it could be a cable, a puck, or a speedo issue? any way to test the components individually?

Thanks
-Mike