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Stevens Instrument Company S48 8-Wire Spark Checker

Manufacturer

Stevens Instrument Company

<h3>About Stevens Instrument Company</h3><p>For more than half a century, <strong>Stevens Instrument Company</strong> has been a trusted name among professional marine technicians, motorcycle mechanics, and small engine specialists. What began as Stevens Experimental — producing some of the earliest coil testers and magnet chargers purpose-built for marine applications — has grown into a third-generation, family-owned operation headquartered in Waukegan, Illinois. That heritage of hands-on craftsmanship and deep industry knowledge still drives every product the company makes today.</p><p>Stevens Instrument's longevity in a competitive market is no accident. The company's philosophy centers on building tools that last, and on maintaining the kind of long-term customer relationships that only come from consistently delivering on that promise. Professional technicians who rely on these tools day in and day out know that a Stevens instrument won't let them down mid-job — a reputation earned over decades of real-world use in marine dealerships, ATV shops, and outboard service centers across North America.</p><h3>What Stevens Instrument Company Makes</h3><p>Stevens Instrument specializes in a focused lineup of high-quality diagnostic and service tools designed for the specific demands of marine and powersports powertrains. Their products cover two critical areas of engine and drivetrain service:</p><ul><li><strong>Spark Checkers:</strong> Stevens Instrument's spark checkers are widely regarded as industry-leading tools for verifying ignition performance on outboards, personal watercraft, and small engines. Models like the S-48 eight-wire spark checker support one to eight cylinders and are engineered from Valox — a material highly resistant to chemicals, UV exposure, and physical damage. Adjustable gap settings accommodate both standard and CDI ignition systems, making them versatile across a wide range of marine and powersports platforms.</li><li><strong>Gearcase Pressure Testers &amp; Fillers:</strong> Proper gearcase maintenance is critical to the longevity of any outboard or sterndrive lower unit. Stevens Instrument's S-34 Gearcase Pressure Tester allows technicians to pressurize outboard and sterndrive gearcases and monitor for leakage — an essential step during lube changes and following any gearcase repair. Paired with their gearcase filler pumps and a comprehensive range of thread adaptors compatible with Mercury, Yamaha, Suzuki, Evinrude, and OMC applications, Stevens provides a complete solution for lower-unit service.</li></ul><h3>Built for the Professional Technician</h3><p>Stevens Instrument tools are not designed for the casual weekend boater — they are engineered for the professional shop environment. Every product reflects the company's deep understanding of what marine and powersports technicians actually need: reliable readings, durable construction, and compatibility across the broad range of engines they service daily. Their broad range of testers covers both magneto ignition and CDI systems, giving shops a single trusted source for ignition diagnostic tooling regardless of the brand on the engine cover.</p><p>Whether you are servicing a high-horsepower offshore outboard, a jet ski, an ATV, or a small utility engine, Stevens Instrument Company offers the specialized tooling to get the job done right. Their commitment to quality and longevity — in both products and customer relationships — has made them a staple in professional marine service facilities for generations.</p>

Part Number

S48
06/02/2036 6:43 PM
Sale Price

$154.76

1 left at this price

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Usually delivered within 2 days

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No Hassle Returns

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Fitment guaranteed

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Product Details

The Stevens Instrument Company S48 is a professional-grade, open-gap spark checker designed for diagnosing ignition systems on engines with 1 to 8 cylinders. This versatile diagnostic tool allows technicians to visually inspect spark quality and strength, making it invaluable for troubleshooting misfires and weak ignition components.

Key Features:

  • Eight-wire capacity for testing 6 and 8 cylinder engines
  • Separates into two identical 4-wire halves by loosening wing nuts for use on smaller engines
  • Adjustable gap mechanism with markings in both inches (1/4" to 1/2") and millimeters
  • Recessed black background for easy spark visibility and prevents carbon tracking
  • Molded Valox housing provides superior resistance to chemicals, UV radiation, and physical damage
  • Includes two ground wires for separate 4-wire operation
  • Sliding mechanism allows precise gap adjustment to simulate different load conditions

This professional spark checker is constructed from durable Valox material that withstands harsh shop environments. The adjustable gap feature allows mechanics to test spark strength under varying conditions, helping to quickly identify weak coils or ignition components. Whether you're working on single-cylinder small engines or V8 automotive applications, the S48's modular design adapts to your diagnostic needs.

Albert was nice to work with over the phone, thank you

Could not figure out from site how long it will be before delivery. Not sure I got the correct shipping discount after increasing the order but satisfied with purchase.

123

Very easy ordering process. Free shipping is a plus.

Processed and shipped out very quickly. I love when a website delivers! It was the best deal on the internet AND they gave free shipping! I will definitely do future business with Autoplicity. Thanks!

I would definetly order from Autoplicity again. Fast curtious service they had just what I wanted and the prices were the best I could find.

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