Sierra Voltage Regulator 18-99439, Replaces 881346T, for Mercury/Mariner 75-115HP and Yamaha 4-Stroke Outboards

The Sierra 18-99439 Voltage Regulator is a direct-fit electrical component for 4 cylinder outboard engines, built to regulate charging voltage and protect the engine's electrical system from overcharging. It is constructed of marine-grade materials to withstand the corrosive marine environment and is designed for quick, straightforward installation in place of the original unit.

This regulator fits Mercury/Mariner 75-115HP 4-Stroke outboards, as well as Yamaha 50-90HP (2005-2006) and Yamaha 115HP (2000-2006) 4-Stroke outboards. It is a direct cross-reference replacement for OEM part numbers 881346T, 68V-81960-00-00, and 6D3-81960-00-00, making it a straightforward swap for boaters replacing a failed or aging factory voltage regulator. Always confirm the part number on your existing regulator or consult your engine's service manual before ordering to ensure correct fitment.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99439
• Weight: 0.85 pounds
• Material: Marine-grade materials
• Compatible Engine Type: 4 Cylinder Outboard Engines
• Fits: Mercury/Mariner 75-115HP 4-Stroke
• Fits: Yamaha 50-90HP (2005-2006) 4-Stroke
• Fits: Yamaha 115HP (2000-2006) 4-Stroke
• OEM Cross Reference: 881346T, 68V-81960-00-00, 6D3-81960-00-00
• UPC: 736983861191

Fitment

• Mercury/Mariner 75-115HP 4-Stroke
• Yamaha 50-90HP (2005-2006) 4-Stroke
• Yamaha 115HP (2000-2006) 4-Stroke

Replaces (OEM)

• 881346T
• 68V-81960-00-00
• 6D3-81960-00-00

Frequently Asked Questions

What does the Sierra 18-99439 voltage regulator do? It regulates the charging voltage produced by a 4 cylinder outboard's stator, protecting the battery and electrical system from overcharging. The Sierra 18-99439 is designed as a direct replacement for the factory regulator on compatible outboards.

Which outboard engines does part 18-99439 fit? The 18-99439 fits Mercury/Mariner 75-115HP 4-Stroke outboards, Yamaha 50-90HP (2005-2006) 4-Stroke outboards, and Yamaha 115HP (2000-2006) 4-Stroke outboards.

Is the Sierra 18-99439 compatible with Yamaha outboards, or only Mercury? Both. In addition to Mercury/Mariner 75-115HP 4-Stroke engines, the 18-99439 is compatible with Yamaha 50-90HP (2005-2006) and Yamaha 115HP (2000-2006) 4-Stroke outboards.

What OEM part numbers does the 18-99439 replace? The Sierra 18-99439 replaces OEM numbers 881346T, 68V-81960-00-00, and 6D3-81960-00-00, so it can be used as a drop-in swap for any of those factory regulators.

How much does the 18-99439 voltage regulator weigh? The Sierra 18-99439 voltage regulator weighs 0.85 pounds.

What is the 18-99439 regulator made of? It is constructed of marine-grade materials, built to hold up to the corrosive conditions of a marine engine compartment.

Is this a genuine Sierra part or an aftermarket equivalent? The 18-99439 is a Sierra-branded voltage regulator sold as a direct-fit replacement for the listed OEM part numbers, not a repackaged factory unit.

Will the 18-99439 work on a 6-cylinder outboard? No. The Sierra 18-99439 is designed specifically for 4 cylinder outboard engines within the listed Mercury/Mariner and Yamaha horsepower ranges.

How do I know if my old regulator matches this part? Check your existing regulator for one of the OEM numbers 881346T, 68V-81960-00-00, or 6D3-81960-00-00, or confirm your engine falls within the Mercury/Mariner 75-115HP or Yamaha 50-90HP/115HP 4-Stroke ranges the Sierra 18-99439 covers.

Does the 18-99439 require special tools to install? It is designed for straightforward installation in place of the original regulator; no special tools beyond standard hand tools are needed, though manufacturer installation guidelines should be followed for proper fit.

What is the UPC for the Sierra 18-99439? The Sierra 18-99439 voltage regulator has UPC 736983861191.