The OBR Mercury Verado inline-6 lower unit is a replacement gearcase offered in new and remanufactured configurations for selected 200, 225, 250, 275 and 300 HP Verado applications. Available configurations include 20-inch, 25-inch and 30-inch driveshaft lengths, with standard and counter-rotation options identified by individual OBR SKUs.

The 200–275 HP catalog family begins with 2005 applications, while the listed 300 HP family begins with 2006 applications. OBR identifies the listed 300 HP units as 4.8-inch Verado gearcases. Exact fitment must be confirmed using the complete engine serial number, original gearcase or OEM number, driveshaft length and required rotation.

Horsepower or external appearance alone cannot confirm compatibility. Select the condition and configuration carefully, then provide the engine serial number before checkout.

  • Manufacturer: OBR Parts
  • Product type: Replacement outboard lower unit/gearcase
  • Available conditions: New and remanufactured
  • Application family: Selected Mercury Verado four-stroke engines
  • Horsepower range: 200–300 HP, depending on SKU
  • 200/225/250/275 HP catalog years: 2005-up
  • 300 HP catalog years: 2006-up
  • Shaft lengths: 20-inch L, 25-inch XL and 30-inch XXL
  • Rotation: Standard or counter rotation, depending on SKU
  • 300 HP housing designation: 4.8-inch
  • Warranty: OBR two-year limited gearcase warranty, subject to full terms
  • Gear oil: Gearcase ships without oil

This listing contains multiple OBR lower-unit configurations and is not a universal 200–300 HP fitment.

For selected 200, 225, 250 and 275 HP Verado applications:

  • Catalog starting year: 2005
  • Standard rotation: 20-, 25- and 30-inch configurations
  • Counter rotation: 25- and 30-inch configurations

For selected 300 HP Verado 4.8-inch applications:

  • Catalog starting year: 2006
  • Standard rotation: 20-, 25- and 30-inch configurations
  • Counter rotation: 25- and 30-inch configurations

Fitment is not confirmed until the selected OBR SKU is matched to the complete Mercury engine serial number, original gearcase/OEM number, required rotation and driveshaft length. Exact model suffixes and gear ratios must be verified before publication and purchase.

  • Do not order by horsepower, model year or appearance alone.
  • Confirm whether the existing gearcase is standard or counter rotation.
  • Match the required 20-inch, 25-inch or 30-inch driveshaft configuration.
  • Do not assume that engine position alone determines rotation.
  • The listed 300 HP OBR configurations are identified as 4.8-inch gearcases.
  • Do not use this listing as proof of fitment for a 5.44-inch, Torque Master, Sport Master or later V6/V8 Verado gearcase.
  • Match the original gear ratio before installation. The ratio mapping for these OBR SKUs must be confirmed.
  • Provide the complete engine serial number and original gearcase/OEM number before checkout.
  • The gearcase ships without oil and must be filled before operation.

Orders are normally processed within 1–2 business days. Delivery estimates and shipping charges depend on the destination, shipment dimensions and selected service.

OBR gearcase assemblies ship without gear oil. Fill the unit with the lubricant and quantity required by the engine manufacturer before operation. Proper shift adjustment is essential. During the first 10 operating hours, vary engine speed, avoid full-throttle starts and follow OBR’s published lower-unit break-in procedure.

Do not install the unit until the selected OBR SKU, shaft length, rotation and original application have been confirmed.

Mariners’ published delivery estimates are 3–7 business days for standard shipping, 2–3 for expedited and one business day for overnight service, subject to location and delays. Shipping policy

Quick Fitment Summary

Specification Mercury Verado Inline-6 Lower Unit | 200–300 HP
Manufacturer OBR Parts
Product Type Replacement outboard lower-unit/gearcase assembly
Conditions New and remanufactured, depending on selected SKU
Engine Family Selected Mercury Verado four-stroke inline-6 applications; verify complete engine serial number
Horsepower 200, 225, 250, 275 and 300 HP, depending on SKU
Verified Catalog Years 200/225/250/275 HP: 2005-up; 300 HP: 2006-up
Shaft Options 20-inch L, 25-inch XL and 30-inch XXL, depending on SKU
Rotation Standard or counter rotation, depending on SKU
300 HP Gearcase OBR catalog identifies the listed 300 HP configurations as 4.8-inch
OBR SKU Families ME-G6-18 through ME-G6-22 and ME-G6-30 through ME-G6-36; N means new and R means remanufactured
Major Exclusions Do not assume fitment for 5.44-inch, Torque Master, Sport Master or later V6/V8 Verado applications
Required Customer Information Complete engine serial number, original gearcase/OEM number, horsepower, shaft length and rotation

How to Select the Correct OBR Mercury Verado Lower Unit

Choosing an OBR Mercury Verado inline-6 lower unit starts with the exact gearcase configuration, not horsepower alone. First, locate the complete engine serial number and any Mercury or OBR number on the original assembly. These identifiers help separate visually similar gearcases that may use a different shaft length, rotation or housing family.

Next, identify the required driveshaft length. The OBR variants on this page include 20-inch L, 25-inch XL and 30-inch XXL configurations. Then confirm rotation from the existing gearcase and propulsion setup. Standard and counter-rotation units are different products; the position of an engine in a multi-engine installation should not be used as the only confirmation.

Finally, match the original gear ratio and housing type. The listed 300 HP configurations are identified by OBR as 4.8-inch gearcases, but ratio mapping and some 200–275 HP technical details still require supplier verification. If any identifier is unavailable, submit the engine serial number and clear photos before ordering. Do not install the unit until the selected SKU has been confirmed.

Application / Compatibility Guide

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What Customers Say

Frequently Asked Questions

Which Mercury Verado engines does this OBR lower unit fit?
The listed OBR configurations cover selected 200, 225, 250, 275 and 300 HP Verado applications. Fitment must be confirmed using the complete engine serial number, original gearcase or OEM number, shaft length and rotation.
What model years are listed by OBR?
OBR identifies the 200, 225, 250 and 275 HP configurations as 2005-up and the listed 300 HP configurations as 2006-up. An exact serial-number cutoff must still be confirmed.
Does this listing fit a 300 HP Verado from 2005?
Do not assume that it does. OBR identifies the listed 300 HP ME-G6 configurations as beginning in 2006. A 2005 engine requires separate serial-number verification.
Which model suffixes are compatible?
VERIFY BEFORE PUBLISHING. Obtain the supported Mercury model numbers and suffixes from OBR and match the customer's complete engine serial number.
Does this page include standard and counter-rotation lower units?
Yes. ME-G6-21, ME-G6-22, ME-G6-35 and ME-G6-36 are counter-rotation configurations. The other listed ME-G6 configurations are standard rotation.
Which shaft lengths are available?
Depending on the selected SKU, configurations are available with 20-inch L, 25-inch XL and 30-inch XXL driveshaft lengths. Counter-rotation options on this page are listed in 25- and 30-inch lengths.
What gear ratio should I select?
VERIFY BEFORE PUBLISHING. The OBR public catalog does not state the ratio for each listed SKU. Match the original ratio and obtain written SKU-to-ratio confirmation before ordering.
How many driveshaft and propeller-shaft splines do these units have?
VERIFY BEFORE PUBLISHING with OBR for every ME-G6 SKU. Do not copy spline specifications from the separate SEI SE221 product.
Is this the same product as an SEI SE221 lower unit?
No. This listing contains OBR Parts ME-G6 SKUs. SEI SE221 is a separate manufacturer and product family with separate configurations and warranty terms.
Does this replace every 4.8-inch or 5.44-inch Verado gearcase?
No universal fitment is claimed. OBR explicitly identifies the listed 300 HP configurations as 4.8-inch units. Do not assume compatibility with 5.44-inch, Torque Master, Sport Master or later V6/V8 Verado applications.
Does the lower unit arrive with gear oil?
No. OBR states that gearcase assemblies ship without oil. Fill the unit with the manufacturer-required lubricant before operation and follow the published break-in procedure.
What warranty and return terms apply?
OBR publishes a two-year limited warranty for gearcases. Mariners Warehouse accepts eligible returns within 14 days from shipment, but installed or used products cannot be returned and approved returns are subject to the published terms and 10% restocking fee.

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