General Specifications
HP / kW
25 HP / 18.6 kW
Displacement
500 cc (30.5 cu in.)
Cylinders
3 (Inline)
WOT RPM
5000 - 6000
Weight
60 kg / 132 lbs
Drive & Lower Unit
Gear Ratio
2.17:1
Shaft Length
15", 20"
Electrical System
Alternator Output 210 Watts
Starting System Manual/Electric
Technical Maintenance Toolkit
Verified service specifications for the Mercury 25hp EFI (3-Cyl 500cc) (2024)
Lubrication
Engine Oil
25W-40 FC-W
Oil Capacity 1.8 Liters
Gearcase Lube 350 ml
Ignition System
Spark Plug
NGK DCPR6E
Firing Order 1-2-3-4
Performance Specs
Idle RPM 700 ± 50
WOT Range 5000-6000
Alternator 210W
Standard Maintenance Intervals
20H Break-in Service
100H Annual Tune-up
300H Water Pump & Seals
Identification
The serial number for the Mercury 25hp EFI (3-Cyl 500cc) is typically found on a plate located on the transom bracket.
Technical Toolkit
Maintenance Compatibility
These models share common service parts with the Mercury 25hp EFI (3-Cyl 500cc):
Model Evolution
History of the Mercury 25HP series over the years:
Category Discovery
Reference Data
Information compiled from Mercury Marine factory service manuals and original sales literature published in 2024.