General Specifications
HP / kW
300 HP / 223.5 kW
Displacement
4400 cc (268.5 cu in.)
Cylinders
8 (V8 (60°))
WOT RPM
3700 - 4000
Weight
393 kg / 867 lbs
Drive & Lower Unit
Gear Ratio
1.46
Shaft Length
25" X-Long, 30" XX-Long, 35" Ultra
Electrical System
Alternator Output 1440 Watts
Starting System Electric (Coastkey)
Technical Maintenance Toolkit
Verified service specifications for the Cox Marine CXO300 Commercial Diesel (2024)
Lubrication
Engine Oil
15W-40 Synthetic Diesel
Oil Capacity 9.5 Liters
Gearcase Lube 1900 ml
Ignition System
Spark Plug
None (Diesel)
Firing Order 1-2-3-4
Performance Specs
Idle RPM 700 ± 50
WOT Range 3700-4000
Alternator 1440W
Standard Maintenance Intervals
20H Break-in Service
100H Annual Tune-up
300H Water Pump & Seals
Identification
The serial number for the Cox Marine CXO300 Commercial Diesel is typically found on a plate located on the transom bracket.
Technical Toolkit
Maintenance Compatibility
These models share common service parts with the Cox Marine CXO300 Commercial Diesel:
Model Evolution
History of the Cox Marine 300HP series over the years:
Category Discovery
Reference Data
Information compiled from Cox Marine Marine factory service manuals and original sales literature published in 2024.