300 HP
Pro XS Performance
Mercury 300 HP Pro XS
V8 · 4.6L
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Tournament-bred performance — lighter weight, a harder hole shot and higher top speed, tuned for bass and bay boats that demand to win.
Specifications
| Horsepower | 300 HP |
| Configuration | V8 (64°) |
| Displacement | 4.6 L / 279 cid |
| Full-throttle RPM | 5200–6000 |
| Dry weight | ~600 lb |
| Alternator | 85 A |
| Gear ratio | 1.75:1 / 1.85:1 |
| Gearcase | 5.44" HD |
| Fuel | EFI · 87 octane |
Specifications are Mercury published figures for this engine platform; exact weight, gearcase and rigging vary by shaft length and configuration — confirm on your quote.
Parts & diagrams for this engine
Genuine parts
Parts that fit your 300 HP Pro XS →
Jump to the parts store, pre-filtered to your engine — kits, water pumps, anodes, filters and more, factory-direct.
Exploded diagrams
Look up the 300 HP Pro XS diagram ↗
Find the exact component on Mercury’s official exploded parts diagrams by serial number or model, then order it here.