Have Merc MCM 4.3 Liter I/O. Am on third tach, currently Quicksilver 704 136, 79-883620-1, 26/06/01. Switch to "ON", see tach read perfect zero. Switch to "START", run engine, see tach wildly gyrate. Configuration switch set to "3", i.e., 6 cylinder. Connect ordinary automotive tach+dwell to...
