MERCURY MERCRUISER GM 4 CYLINDER 1985-1989 WORKSHOP REPAIR SERVICE MANUAL #10 NUMBER 10 Models & Year Marine Engines GM 4 Cylinder 1985 1986 1987 1988 1989 153 - 181 CID (2.5L - 3.0L) Models Covered in this Manual MCM 120 MR MCM 120 ALPHA I MCM 2.5L MCM 140 MR MCM 140 ALPHA I MCM 3.0L SEA RAY 3.0L Note that the MCM 2.5L - Same as MCM 120. MCM 3.0L Sea Ray 3.0L- Same as MCM 140 (Later Models are rated at 130 HP and have 9.2:1 Compression ratio)