View Full Version : Tach troubles

03-14-2008, 09:56 PM
I currently own a 1980 Mastercraft with 351W engine. When I bought it the coil resistor was disconnected. The old breaker points were replaced with new breakerless ignition components in the distributor. I researched the new ignition parts and the installation instructions said it was no longer necessary. I got rid of it while cleaning up the rats nest of wiring during the latest portion of refurbishment on the boat. I noticed the tachometer has been showing roughly 2 times the actual RPM since I bought the boat. I'm thinking the resistor was necessary to drop the voltage across the system. The switch on the back of the tach is set for an 8 cyliinder engine. I tried switching to other settings to troubleshoot the tach, and it seeems to be working correctly. I'm thinking this is an old fashioned type tach that uses the pulses to directly drive the needle deflection instead of processing it digitally. The tach seems to be original equipment.

Any help from the "old school" Ford boys?