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Stevens Instrument Company S34 Gearcase Pressure Tester for Outboard and Sterndrive

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

S34
06/02/2036 6:42 PM
Sale Price

$173.33

In Stock (10+)

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Usually delivered within 2 days

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FREE SHIPPING

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Stevens Instrument Company S34 Gearcase Pressure Tester is an essential diagnostic tool for marine mechanics and boat owners working with outboard motors and sterndrive gearcases. This professional-grade pressure tester helps identify leaks and seal failures quickly and accurately, ensuring proper gearcase integrity before costly damage occurs.

Key Features:

  • Pressure tests outboard and sterndrive gearcases to detect seal leaks and failures
  • Fitted with standard 3/8-16 inch vent plug thread for universal compatibility
  • Easy-to-read pressure gauge for quick leak detection
  • Simple operation: pressurize the gearcase and observe gauge for pressure drop
  • Includes adapter for testing intermediate housing on OMC Sterndrives
  • Compatible with additional thread adaptors (sold separately) for all gearcase types

When to Use:

Pressure testing should be performed during routine lubricant service operations and following any gearcase repairs. If leakage is apparent due to loss of lubricant, simply pressurize the unit and inspect for signs of seepage around seals, shift rods, and driveshaft areas. Following repairs, gearcases can be checked before filling by pressurizing and submerging in a test tank to visually identify leak points.

This tool helps diagnose problems with shift rod seals, driveshaft seals, and other gearcase components before they lead to water intrusion or complete gearcase failure. Regular pressure testing is a critical preventive maintenance step for preserving the life of your lower unit.

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Ordered my part on Monday and its scheduled to be here by this coming Monday. Fast shipping and great customer customer service.

Please ship this product as soon as you can. I'd like to receive it this week if possible. Thanks in advance.

so far very easy and quick,, tied in with amazon which was a little freaky but made it easy. now lets see if they deliver.

OK

good prices!!!!!!!!!! Fast shipping thanks

Recieved order and all parts were packaged well and made the shipment without any damage. Very pleased will not hesitate to order again

Good price

Hard to find classic car parts. This was easy!

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