General Specifications
HP / kW
90 HP / 67.0 kW
Displacement
1522 cc (92.9 cu in.)
Cylinders
3 (Inline)
WOT RPM
5000 - 5750
Weight
170 kg / 375 lbs
Drive & Lower Unit
Gear Ratio
2.33:1
Shaft Length
20", 25"
Electrical System
Alternator Output 720 Watts
Starting System Electric
Technical Maintenance Toolkit
Verified service specifications for the Mercury 90hp OptiMax (2010)
Lubrication
Engine Oil
Mercury OptiMax/DFI Oil
Gearcase Lube 665 ml
Ignition System
Spark Plug
NGK IZFR6J
Gap Setting 0.040"
Firing Order 1-2-3-4
Performance Specs
Idle RPM 700 ± 50
WOT Range 5000-5750
Alternator 720W
Standard Maintenance Intervals
20H Break-in Service
100H Annual Tune-up
300H Water Pump & Seals
Identification
The serial number for the Mercury 90hp OptiMax is typically found on a plate located on the transom bracket.
Technical Toolkit
Maintenance Compatibility
These models share common service parts with the Mercury 90hp OptiMax:
Model Evolution
History of the Mercury 90HP series over the years:
Category Discovery
Reference Data
Information compiled from Mercury Marine factory service manuals and original sales literature published in 2010.