I finally got my TFI put on and set to their settings. I want to dial it in a bit more. They say to start at 1800 rpm. Now I do not have a tack. How good are the rpm testers? Are the ones for around $25 worth it?
Don't go crazy, estimate it, you'll see the difference as you dial it in anyway. 1800-2000 should be easy enough to estimate and it's not that critical.