Engine acting up? Don’t let a faulty part keep you off the water. This genuine Mercury Marine GROOVE PIN restores reliable performance and gets you back to what you love.

Built with Mercury Marine’s precision engineering, this component ensures reliable operation across all engine RPM ranges. Part number 821539 is manufactured to exact Mercury Marine factory specifications for precision installation and optimal performance. Constructed from premium marine-grade materials designed to withstand harsh saltwater and freshwater environments.

Why risk your Mercury engine with questionable aftermarket parts? Genuine part 821539 is built to last, backed by Mercury Marine’s decades of marine engineering expertise and proven reliability.

Compatible Mercury Marine Engines

FITS: 100-105HP MARINER, MERCURY (EFI)

• Fits MARINER, MERCURY 100-105HP engines
• Compatible HP: 100HP, 105HP
• Model types: EFI
• Covers 24 serial number ranges
• Configurations: Jet Drive, Outboard
• OEM genuine Mercury Marine part

COMPLETE SERIAL NUMBER COMPATIBILITY:

100HP Models

• 100HP EFI (Mariner): 0P459572-2B059605, 1B227000-1B366822, 1B366823-2B059605
• 100HP EFI (Mercury): 0P459572-2B059605, 1B227000-1B366822, 1B366823-2B059605
• 100HP OUTBOARD (Mariner): 0A722297-0D283221, 0D283222-0G760299, 0G760300-0G965520, 0P017000-0P058999, 9523034-9793576, 9793577-0P016999
• 100HP OUTBOARD (Mercury): 0B209468-0D283221, 0D283222-0G760299, 0G760300-0G965520, 0P017000-0P058999, 9523034-9793576, 9793577-0P016999

105HP Models

• 105HP JET (Mariner): 0D082000-0G303045, 0G303046-0G760299
• 105HP JET (Mercury): 0D082000-0G303045, 0G303046-0G760299

Looking for your Mercury engine serial number? Our helpful guide shows you exactly where serial numbers are located on different engines.

Verification & Support

Verify part 821539 works with your Mercury using our parts finder tool. Have questions? Reach out using the contact buttons at the bottom of this page — our team is here to help by text, call, or email

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