Sierra 18-9801 Multi Meter/DVA Tester

Whether you're troubleshooting a stubborn misfire on the water or prepping your Mercury outboard for the season, having the right diagnostic tool makes all the difference. The Sierra 18-9801 steps in as your go-to multi-meter and DVA tester, specifically tuned for Mercury ignition systems. This isn't just another multimeter—it's built to handle the high-voltage peaks that standard tools can't touch, giving you precise readings to pinpoint issues fast.

Why Your Mercury Outboard Needs Reliable Ignition Testing

Mercury engines are powerhouses, but their CD ignition systems—relying on stators, triggers, and power packs—can throw curveballs like weak spark, no-start conditions, or intermittent power loss. Symptoms often point to failing components under load, especially after saltwater exposure or hours of hard running. Peak voltage testing via DVA (peak volts) reveals the truth: is your stator outputting 200-400V? Is the trigger hitting 6-10V? Without this, you're guessing—and guessing costs time and money on the trailer or worse, mid-lake.

Boat mechanics swear by tools like this because they bridge the gap between basic voltage checks and pro-level diagnostics. It measures DC volts, AC volts, resistance, and crucially, DVA for those fleeting ignition pulses that multimeters miss. Think of it as X-ray vision for your engine's electrical heart.

Key Capabilities That Set It Apart

• Versatile Meter Functions: DC/AC voltage, ohms, and peak voltage capture—essential for full-system sweeps.
• DVA-Specific Design: Catches millisecond-high ignition voltages up to 1000V, far beyond generic testers.
• Rugged Build for Marine Use: Handles the humidity, vibrations, and salt you encounter dockside or afloat.
• Easy Read Display: Backlit LCD for low-light troubleshooting, whether in the engine bay or under the console.
• Color-Coded Leads: Quick connections to stator leads, trigger wires, or power pack inputs—no fumbling with tiny pins.

Step-by-Step: Testing Your Mercury Ignition Like a Pro

Grab your 18-9801, fire up the engine (or crank it for trigger tests), and follow these battle-tested steps—drawn from years of shop experience on everything from 2-strokes to modern Optimaxes.

1. Stator Output Check: Disconnect the yellow stator wires at the power pack. Set to DVA, ground black lead to engine block, red to each yellow wire. Crank or run at 3000 RPM—expect 180-400V per leg. Low? Bad stator windings.
2. Trigger Module Test: Purple wires to power pack. DVA mode, one lead to purple, other to ground. 4-6V cranking, up to 10V running. Below spec? Time for a trigger swap.
3. Power Pack Input: Orange wires from battery/charging. AC volts at idle should hover 12-14V. DVA confirms no hidden drops.
4. Resistance Scans: Ohms mode verifies stator (under 1 ohm between legs, infinite to ground) and trigger coils. Catches shorts early.
5. Spark Strength: Inline with plug wire—DVA should read 300-800V or more for healthy fire.

Pro Tip: Always test hot—components act up under heat. And log your numbers; trends spot wear before failure. This tester's accuracy has saved countless hauls from the repair yard.

Real-World Wins from Boaters and Techs

One offshore angler nailed a no-spark issue on his 150hp Verado: stator DVA was 120V on one leg—replaced it, back fishing same day. A lake racer caught a flaky trigger dropping to 2V under load, preventing a DNF. It's not flashy, but it delivers results when stakes are high—your time, your trip, your engine's life.

Compatible across Mercury's lineup, from classics like 40-90hp 2-strokes to fuel-injected 4-strokes, as long as it's CDI or EFI ignition. Pair it with a service manual for model-specific specs, and you're golden.

Frequently Asked Questions

Equip yourself with the Sierra 18-9801 and turn diagnostics from dread to done. Reliable spark starts here.