MerCruiser Alpha One Gen I complete standard-rotation sterndrive

Alpha OneĀ® Gen II Sterndrive Applications; Counter Rotation

Shop Alpha One Gen II counter-rotation sterndrive replacements for compatible MerCruiser applications. Compare SE116 complete drives by gear ratio, then verify your existing ratio and rotation before ordering.

Alpha OneĀ® Gen II Sterndrive Applications; Counter Rotation

Shop MerCruiser Alpha One Gen II counter-rotation lower units and complete sterndrives (1991-present), purpose-built for twin-engine port-side installations. Counter-rotation gearcases spin opposite to standard rotation to cancel out prop torque steer in dual-engine boats.

Find the correct counter-rotation Alpha One Gen II sterndrive for your port-side engine below.

A Clearer Way to Select Your Replacement Drive

Compare the configuration details that matter before choosing a sterndrive.

OEM-COMPATIBLE FITMENT

Engineered for direct replacement

25+ YEARS SERVING BOATERS

Trusted marine parts experience

3-YEAR WARRANTY

Coverage on select lower units

FITMENT SUPPORT

We'll help verify your lower unit

How to Choose the Correct Alpha One Gen II Counter-Rotation Sterndrive

Choosing the correct Alpha One Gen II counter-rotation sterndrive starts with identifying the drive already installed on your boat. Before selecting an SE116 counter rotation replacement, confirm the drive generation, existing gear ratio, rotation and identification information rather than choosing by appearance or engine horsepower alone.

Use the checklist below to narrow the available MerCruiser Gen II counter rotation sterndrive options and reduce the risk of ordering the wrong configuration.

Verify Before You Buy

  • Alpha One Gen II drive generation
  • Counter-rotation configuration
  • Existing overall gear ratio
  • Engine model
  • Engine serial number
  • Drive serial number
  • Existing part or cross-reference number
  • Complete sterndrive required vs upper or lower unit only

Alpha One Gen II Counter-Rotation Gear Ratio Guide

The correct Alpha One Gen II gear ratio must match the boat's verified drive configuration. Counter-rotation SE116 complete-drive applications are offered across multiple ratios, so do not select a replacement from engine horsepower or appearance alone.

Gear Ratio SE116 Counter-Rotation Drive
1.47:1 Complete sterndrive assembly for counter-rotation applications. Shop the 1.47 C.R. complete drive and verify the existing ratio, rotation and drive identification before ordering.
1.62:1 Complete sterndrive assembly for counter-rotation applications. Shop the 1.62 C.R. complete drive and verify the existing ratio, rotation and drive identification before ordering.
1.81:1 Complete sterndrive assembly for counter-rotation applications. Shop the 1.81 C.R. complete drive and verify the existing ratio, rotation and drive identification before ordering.
1.94:1 Complete sterndrive assembly for counter-rotation applications. Shop the 1.94 C.R. complete drive and verify the existing ratio, rotation and drive identification before ordering.

Complete Sterndrive or Counter-Rotating Lower Unit?

Not every Alpha One Gen II repair requires the same assembly. Identify where the failure is located and confirm which components can safely remain in service before purchasing a replacement.

Complete Counter-Rotation Sterndrive

  • Choose a complete Alpha One Gen II counter-rotation sterndrive when the repair requires both the upper and counter-rotation lower drive assemblies
  • Ensure the selection is subject to verified fitment

Counter-Rotating Lower Unit

  • Choose a counter-rotating lower unit when inspection confirms the existing upper assembly can remain in service
  • Ensure the upper assembly is compatible with the required lower-unit configuration

Upper Unit

  • Choose an Alpha One Gen II upper unit when the repair is isolated to the upper assembly
  • Ensure the existing lower unit remains serviceable and compatible with the required overall drive configuration
An informational comparison graphic titled 'STANDARD VS COUNTER ROTATION' showing two outboard motors and two propellers, with text explaining the difference in propeller direction when viewed from behind. The background is a real marina scene with water and boats, but the image functions as an explanatory diagram rather than a straightforward product photo.

Standard vs Counter-Rotation Alpha One Gen II Sterndrives

Alpha One Gen II sterndrives are available in standard-rotation and counter-rotation configurations, and the two should not be selected interchangeably. Verify the existing drive rotation, gear ratio and identification information before choosing the correct MerCruiser Alpha One Gen II replacement.

Standard Rotation

Choose an Alpha One Gen II standard-rotation sterndrive when the existing drive and application information confirm a standard-rotation configuration. Match the replacement to the verified gear ratio, drive generation and current identification before ordering.

Counter Rotation

Choose an Alpha One Gen II counter-rotation sterndrive when the documented application requires a counter-rotating drive. SE116 counter-rotation complete drives are offered in multiple gear ratios, so confirm both rotation and ratio before selecting your replacement.

Shop Alpha One Gen II Counter-Rotation Sterndrives by Gear Ratio

Choosing the correct Alpha One Gen II counter rotation gear ratio is one of the most important steps when replacing a complete sterndrive. Browse available SE116 counter rotation configurations by ratio, then verify your existing Alpha One Gen II gear ratio, drive identification and rotation before ordering.

Alpha One Gen II Counter-Rotation Sterndrive Replacement Options

Shop Alpha One Gen II counter-rotation sterndrive replacements for compatible MerCruiser applications where a counter-rotating complete drive is required. This collection focuses on SE116 counter rotation configurations and gives boat owners a clear way to compare available replacement options by drive family, rotation and overall gear ratio.

Choosing the correct MerCruiser Alpha One Gen II counter rotation sterndrive requires more than matching the appearance of the existing outdrive. Confirm that the installed drive is Alpha One Gen II, verify the counter-rotation requirement, identify the existing gear ratio and compare the available product information before ordering. Current counter-rotation shopping paths may include 1.47:1, 1.62:1, 1.81:1 and 1.94:1 ratios, so the exact ratio should be matched to the verified application rather than selected from horsepower alone.

What Customers Say

Frequently Asked Questions

How do I know if I need an Alpha One Gen II counter-rotation sterndrive?

Verify the rotation designation of the existing drive before ordering an Alpha One Gen II counter-rotation sterndrive. Use the drive identification, gear ratio, current part information and documented boat configuration rather than assuming rotation from the drive's position on the boat.

Is an Alpha One Gen II counter-rotation drive the same as a standard-rotation drive?

No. An Alpha One Gen II counter-rotation sterndrive and a standard-rotation sterndrive use different rotation configurations and should not be treated as interchangeable. Match the replacement to the verified rotation required by the existing installation.

Does the port-side Alpha One Gen II drive always use counter rotation?

No. Boat position alone does not prove whether an Alpha One Gen II sterndrive requires standard or counter rotation. Verify the current drive designation, ratio, part information and propeller configuration before ordering.

What gear ratios are available for Alpha One Gen II counter-rotation sterndrives?

SE116 complete counter-rotation shopping paths include 1.47:1, 1.62:1, 1.81:1 and 1.94:1 configurations. The correct Alpha One Gen II gear ratio must be verified against the existing drive and selected product application rather than chosen from horsepower alone.

How do I find the gear ratio of my Alpha One Gen II sterndrive?

Start with the existing drive identification and any readable ratio, serial or part information. If those details are missing or unclear, use service records or have the installed drive properly identified before purchasing a replacement Alpha One Gen II sterndrive.

What does SE116 mean on an Alpha One Gen II replacement sterndrive?

SE116 is used in Sterndrive Engineering replacement applications for MerCruiser Alpha One Gen II drive assemblies. Always use the complete product title, gear ratio, rotation and application information because the SE116 family includes multiple configurations.

Should I buy a complete counter-rotation sterndrive or only a lower unit?

Choose a complete counter-rotation sterndrive when the repair requires both upper and lower drive assemblies. If inspection confirms the existing upper can remain in service, a compatible Alpha One Gen II counter-rotating lower unit may be the more appropriate replacement path.

Can I replace a standard Alpha One Gen II drive with a counter-rotation drive?

Do not substitute an Alpha One Gen II counter-rotation drive for a standard-rotation unit unless the verified boat configuration specifically requires that change. Rotation is a fitment requirement and should be confirmed before purchasing the replacement.

What information should I send for an SE116 compatibility check?

For an SE116 compatibility review, provide the engine model and serial number, existing drive serial number, current part or casting number, gear ratio, rotation information and clear photos of the installed sterndrive. More complete identification reduces uncertainty when comparing replacement options.

Need Help?

Still Can't Find the Right Marine Part?

Finding the right replacement part shouldn't be frustrating. If you can't locate the marine part you need, our experienced support team is here to help. Whether you have a part number, engine model, or simply need expert guidance, we'll help you find the correct replacement so you can get back on the water with confidence.

Trusted by 50,000+ boat owners across the USA

A man wearing a navy blue polo shirt with a circular logo sits at a desk holding a metal engine component, with a laptop in front of him and a boat propeller on the table. A dark blue informational overlay on the right lists benefits like 'Talk to an Expert' and 'Find the Right Part'.
  • Expert Marine Support

    Our team has years of experience in marine parts.

  • Fast Response

    We respond quickly to get you the help you need.

  • Find Compatible Parts

    We make sure you get the right part the first time.

  • Huge Selection

    Access to 50,000+ marine parts & accessories.

Have a Part Number or Engine Model?

Send it to us and our experts will help you find the exact part you need.

Recently Viewed Products