1998+ Mercury Mariner 25HP Bigfoot Service Manual, Page 82Get this manual

IGNITION
Tool: MultimeterDVA Tester 91-99750A1
Component Test Selector SwPosition DVA Lead Red DVA Lead Black Voltage Reading(1) 300-3000 RPM

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives