wacky tachy

[nola mike]

Almost have the craft free of gremlins. I had a miss when warm last week. Replaced the coil and cleaned connections, which has cured that. Since then the tach has been floating, bouncing and reading higher than it should. Seems worse at higher speed, and also worse when hitting the trim button. Leads me to think that it's an electrical connection, but I cleaned everything at the coil, the gauge, and the ignition switch. Any ideas on how to troubleshoot? May just buy a cheap tach to see if the problem is gauge or wiring