I'm new to the forum and I have a question that I hope is very simple, but likely isn't at all. I recently got a new (to me) bike and absolutely love it. It's actually my first bike and I couldn't be happier with my purchase. Sure, it has a little bit of cosmetic damage and doesn't run perfectly, but it's so more fun that I've ever had in a car.
Still, now that I've had it a few weeks I've finally convinced myself to start unlocking some of the potential I have been ignoring in the interest of my continued well being. I finally redlined my bike in first gear and I noticed something a bit strange. For some reason the bike peaks at 12k rpm of the 13.5k indicated on the tachometer; it tugs hard right up to that cutoff too. I'm not sure what to think of this; aside from the fact that the carbs seem to need to be synced a bit the bike runs great despite its 20k miles. The only possibility I can think of is that one of the previous modifications to the bike (before I owned it) has had some sort of effect on the tachometer. For example, I know that the front sprocket has been replaced with a sprocket with fewer teeth (-1 if I remember correctly).
I'm not experienced enough to solve this problem myself, but any help solving it would be greatly appreciated. I've already become quite attached to my bike and I'd like to get it running at its full potential. Thank you much.