1996 Johnson/Evinrude Outboards 25, 35 3-Cylinder Service Manual, Page 253Get this manual
Tachometer Circuit Tests Perform the following tests if the tachometer does not operate
The tachometer circuit is driven by the stator outputBefore proceeding, check condition of the stator following Stator Resistance Tests, this section
Important
Verify that all engine and boat wiring and connectors are in good condition
Do not energize the primer while performing these tests