I just noticed it, sometimes when I cruise down the highway I catch a glimpse of my tachometer and it starts "twitching", it'll stop working for a split second and them work normal again. It doesn't happen too often and I haven't noticed anything in city driving, what could this be?

Also, my speedo is wayyyyy off, about 10%, 66-68 on my speedo is 60 "true" mph. I'm riding on 205/50/17's which is about 0.2% smaller than my stock rims, I don't think this is the problem, how much should I expect to pay for a recalibration?

 

check ur wires. The twitching Tach is most likely a loose wire...

 

What do you mean by "stop working?"

 

When I say stop working I mean I'll be cruising @80mph and my tachometer will show 0 rpms instead of 3300.