General Specifications
HP / kW
25 HP / 18.6 kW
Displacement
432 cc (26.4 cu in.)
Cylinders
2 (Inline)
WOT RPM
5000 - 6000
Weight
57 kg / 126 lbs
Drive & Lower Unit
Gear Ratio
2.08:1
Shaft Length
15, 20
Electrical System
Alternator Output 192 Watts
Starting System Manual/Electric
Technical Maintenance Toolkit
Verified service specifications for the Yamaha F25 Portable EFI (2024)
Lubrication
Engine Oil
Yamalube 4-Stroke
Oil Capacity 1.1 Liters
Gearcase Lube 370 ml
Ignition System
Spark Plug
NGK DPR6EB-9
Gap Setting 0.035"
Firing Order 1-2-3-4
Performance Specs
Idle RPM 700 ± 50
WOT Range 5000-6000
Alternator 192W
Standard Maintenance Intervals
20H Break-in Service
100H Annual Tune-up
300H Water Pump & Seals
Identification
The serial number for the Yamaha F25 Portable EFI is typically found on a plate located on the transom bracket.
Technical Toolkit
Maintenance Compatibility
These models share common service parts with the Yamaha F25 Portable EFI:
Model Evolution
History of the Yamaha 25HP series over the years:
Category Discovery
Reference Data
Information compiled from Yamaha Marine factory service manuals and original sales literature published in 2024.