The Tach on my 1987 Pachanga is reading around 1000 RPM's higher than the engine is actually running. When the motor is off it returns back to 1100 RPM's. I have tested the engine with a RPM meter to confirm my findings. Is there a calibration adjustment on Tach's or do I just need to look for new instruments. If I need a new Tach/instruments please provide recommendations.

i have found on my tach, that there is an adjustment on the back. It uses something similiar to a wand used in radio repairs. I just took a metal coat hangar and filed it down to a straight edge, basically you just need a very small screwdriver, don't know about your tack, but both my original, and my aftermarket tachs had an adjustment pot on the back.

The adjustment on the back is usually a selector for 4, 6, or 8 cylinder engine. Check your ignition secondary for loose/cracked wires, cap etc, that can cause high readings. If that's not the problem, buy a new tach.
Gary

that is one of the adjustments, but there is a calibration adjustment also