🏷️ Basic Information Identification Make: Mercury MerCruiser Model: GM 4 Cylinder Marine Engines Year: 1985-1989 Generation: N/A 📋 Manual Details Description Manual Type: Workshop Repair Service Manual Manual Identifier: #10 Language: English Format: PDF Download ⚙️ Engine Specifications General Engine Family: GM 4 Cylinder Displacement Cid: 153 - 181 Liters: 2.5L - 3.0L Models Covered Model Codes: MCM 120 MR, MCM 120 ALPHA I, MCM 2.5L, MCM 140 MR, MCM 140 ALPHA I, MCM 3.0L, SEA RAY 3.0L Power Output Horsepower Mcm 120: 120 HP Horsepower Mcm 140: 140 HP (Later models 130 HP) Horsepower Sea Ray 3 0L: 130 HP (Later models) Compression Ratio Mcm 140 Sea Ray 3 0L Later Models: 9.2:1 Notes Mcm 2 5L Equivalence: Same as MCM 120 Sea Ray 3 0L Equivalence: Same as MCM 140 (Later Models) 🔧 Transmission Drive Systems Outdrive Types: Alpha I, MR 🔧 Maintenance Fluid Recommendations Engine Oil Type: Refer to manual for specific viscosity and type (e.g., SAE 25W-40 marine oil) Engine Oil Capacity: Refer to manual (typically 5 quarts / 4.7 liters for 3.0L) Cooling System Type: Closed cooling or raw water cooling (refer to specific model) Service Intervals Recommended Service Frequency: Annually or every 100 hours of operation (whichever comes first, refer to manual) Tune Up Spark Plug Gap: Refer to manual for specific engine configuration Ignition Timing: Refer to manual for specific engine configuration