This listing is for a New Outboard Extension Kit manufactured by Bay Manufacturing, designed to add 5 inches to the shaft length of compatible Mercury outboard motors.
Each kit includes a 1-year warranty and may arrive painted black or unpainted with a clean sandblasted finish, depending on the production batch.
This 5" extension kit is engineered for durability, using stainless steel shafts and hardware, and a spacer housing cast from the same alloy series as OEM components.
This specific kit fits motors transitioning from 20" to 25" shaft length.
Product Features
- Adds 5 inches to your Mercury outboard’s shaft length
- Compatible with a wide range of 135–250 HP models
- Heavy-duty stainless steel shafts & studs
- OEM-grade spacer housing for long-term durability
- Ideal for reducing cavitation and improving performance on deeper transoms
Compatible Serial Numbers
- A904646 & Up – 135 HP
- D082000 & Up (XR6) – 135, 150 HP
- OG303046 & Up (XR6) – 135, 150, 175, 200 HP
- 1B073074 & Up (Optimax) – 135 HP
- 4868998 & Up (V-6) – 150 HP
- B242885 & Up (XR4 Magnum) – 175 HP
- 0T908388 & Up (Optimax) – 175 HP
- 6618751 & Up (XR4 Magnum) – 175 HP
- 5363918 & Up (V-6) – 200 HP
- C100861 & Up (XR1 V-6) – 200 HP
- 5628028 & Up (V-6) – 200 HP
- 0T235136 & Up (EFI 2.5L) – 200 HP
- OG283148 & Up (Optimax) – 225 HP
Kit Contents
- (1) 5" Extension Housing
- (1) 5" Driveshaft
- (1) 5" Shift Shaft
- (1) 5" Water Tube
- (5) Studs & Nuts
- (1) Screw
- (2) Dowel Pins
Additional Information
- Fits Mercury 135–250 HP 2-Stroke V6 engines per model/serial specifications listed.
- Not eligible for return except under warranty claim conditions.
Shipping Information
Additional shipping fees to Alaska, Hawaii, U.S. Territories, or international destinations will be calculated after checkout.
A PayPal request will be emailed for any additional charges.
(Some items may be excluded from international shipping.)
Customer Support
For questions or to confirm compatibility, please email customerservice@marinepartswarehouse.com .
Please include your engine model or serial number to help confirm proper fitment before ordering.
