2000 Johnson/Evinrude SS 25, 35 3-Cylinder outboards Service Manual, Page 215Get this manual
Starter System Voltage Drop Test By making systematic check of the starter system, any component or electrical connection having excessive resistance can be located
Avoid accidental starting of engine while servicing; twist and remove all spark plug leads
Clean and retighten, or replace, any connection, cable, or component having greater than specified voltage drop[}] 1Connect voltmeter positive lead to battery positive postConnect voltmeter negative lead to starter solenoid positive terminalTurn key switch to START to crank engineVoltage reading should not exceed 0.3 voltINotell Step 2, connect the voltmeter leads only while the
engine is cranking, or damage to the voltmeter can occur
2Connect voltmeter negative lead to the starter side of the starter solenoid terminalWhile cranking engine, connect voltmeter positive lead to starter solenoid opposite terminalVoltage reading should not exceed 0.2 voltRemove voltmeter positive lead from starter solenoid and stop cranking enginelead terminalConnect voltmeter negative lead to starter motor terminalTurn key switch to STARTVoltage reading should not exceed 0.2 volt