SEI SE116 Alpha One Gen II Lower Unit | 2.00 & 2.40 Ratio | 90-116-02H | Replaces 815822A45

SEI SE116 — Alpha One Gen II Lower Unit | 2.00 & 2.40 Ratio Only | 90-116-02H | Replaces MerCruiser 815822A45

SEI SE116 HA lower unit (part number 90-116-02H) replaces MerCruiser Alpha One Gen II sterndrives from 1991 to present. This unit replaces 2.00 and 2.40 ratio lower units only — confirm your existing gear ratio before ordering. Uses the latest-style speedometer fitting (OE# 860382) — this fitting is not included and is required for a working speedometer. SEI 3-year fault-free warranty included. Not eligible for free shipping.

Important — confirm before ordering:

• Replaces 2.00 and 2.40 gear ratio units only — will not fit other ratios
• Speedometer fitting OE# 860382 (latest style) required — not included

Confirm Fitment Before Ordering

Confirm your MerCruiser Alpha One Gen II gear ratio is 2.00 or 2.40 before ordering. Contact us with your MerCruiser engine and sterndrive model and serial number by email, text, or live chat and we’ll verify SE116 is the correct lower unit for your application.

Part Specifications

• SEI Part Number: 90-116-02H
• Model: SE116 HA
• Type: Aftermarket replacement lower unit
• Replaces: MerCruiser Alpha One Gen II lower units, 1991 to present
• OEM Cross-Reference: MerCruiser 815822A45
• Gear Ratios: 2.00 and 2.40 only — will not replace other ratio units
• Speedometer Fitting: Latest-style OE# 860382 required — not included
• Warranty: SEI 3-year fault-free warranty
• Shipping: Not eligible for free shipping
• Vendor: Sterndrive Engineering (SEI)
• Related Items: SE116 Anode Kit | SEI 90-116-05K | SE116 Aluminum Anode Kit | SEI 90-116-05ATK

Additional Information

• Vendor: Sterndrive Engineering (SEI)
• Part Number: 90-116-02H
• OEM Cross-Reference: MerCruiser 815822A45
• Application: MerCruiser Alpha One Gen II, 1991 to present
• Gear Ratios: 2.00 and 2.40 only
• Warranty: SEI 3-year fault-free
• Shipping: Not eligible for free shipping

Installation Notes

Install following the applicable MerCruiser service manual for the Alpha One Gen II sterndrive. Obtain speedometer fitting OE# 860382 (latest style) before installation — it is required for a working speedometer and is not included with this lower unit. Install a fresh anode kit at the same time — the SEI 90-116-05K (zinc) or SEI 90-116-05ATK (aluminum, for freshwater applications) are the correct companion kits for the SE116.

SEI Warranty

All SEI products are warranted against defects in material and workmanship for either one (1) year or three (3) years from the date of actual purchase, as applicable. Proof of purchase is required. These warranties are the sole and exclusive warranty provided by SEI; all other warranties and potential damages are limited and excluded. Brunswick Corporation is the Original Equipment Manufacturer (OEM). Sterndrive Engineering, Inc. (SEI) has no affiliation with Brunswick Corporation. MerCruiser, Alpha One, and Gen II are trademarks of Brunswick Corporation. As with any aftermarket product, OEM warranties will not apply to SEI products or to products damaged due to the operation of an SEI product.

Frequently Asked Questions

Q: How do I confirm my MerCruiser Gen II is a 2.00 or 2.40 ratio unit?
A: Your gear ratio is stamped on a tag or label on the sterndrive lower unit, or listed in the MerCruiser parts manual for your sterndrive serial number. The SE116 90-116-02H replaces 2.00 and 2.40 ratio units only. Contact us with your sterndrive serial number by email, text, or live chat if you need help identifying your ratio before ordering.

Q: What is the speedometer fitting OE# 860382 and why is it required?
A: MerCruiser updated the speedometer pitot tube fitting design on the Alpha One Gen II. The SE116 uses the latest-style fitting (OE# 860382). If your existing sterndrive used an older-style fitting, you will need to obtain the 860382 fitting separately before installation to maintain a functioning speedometer. This fitting is not included with the SE116.

Q: Does the SE116 replace all Alpha One Gen II lower units?
A: No — the SE116 90-116-02H replaces 2.00 and 2.40 gear ratio Gen II lower units only. Other Gen II gear ratios require a different SEI lower unit. Confirm your ratio before ordering.

Q: Which anode kit do I need for the SE116?
A: For saltwater or brackish water applications, use the zinc anode kit SEI 90-116-05K. For freshwater applications, use the aluminum anode kit SEI 90-116-05ATK. Install a fresh anode kit at the same time as the lower unit.

Q: Is the SE116 fully compatible with OEM MerCruiser Alpha One Gen II components?
A: Yes — SEI replacement lower units, including all internal parts, are designed to be fully compatible and interchangeable with the OEM drives. The SE116 directly replaces MerCruiser part number 815822A45 for 2.00 and 2.40 ratio applications.