Mercury 305 CID - Tune-Up Specifications

MAINTENANCE - 1B-790-823225--1 1096
Tune-Up Specifications
Tune up specifications for the Gen + engines start on page 10.
Model
MCM
5.0L Alpha
MCM
5.0LX Alpha
MCM
5.7L Alpha
MCM 350
Magnum
Alpha
MCM
5.7L Bravo
Propshaft Rating
HP (KW)
1
190 (141) 205 (152) 235 (175) 250 (186) 250 (250)
Number of Cylinders V-8
Displacement 305 CID (5.0L) 350 CID (5.7L)
Bore/Stroke
In. (mm)
3.7 x 3.48 (95 x 88.4) 4.0 x 3.48 (101.6 x 88.4)
Compression Ratio 9.1:1 9.3:1 9.1:1
Compression Pressure 150 PSI (1034 kPa)
Idle RPM In Neutral
2
650-700
Maximum RPM
(at W.O.T.)
4200-4600 4400-4800
Oil Pressure
(at 2000 RPM)
30-60 PSI (207-414 kPa)
Minimum Oil Pressure
(at Idle)
4 PSI (28 kPa)
Mechanical Fuel
Pump Pressure
(at 1800 RPM)
3-7 PSI (21-48 kPa)
Electrical
System
12 V Negative (–) Ground
Minimum Battery
Requirements
375 cca/475 mca/90 Ah
Firing Order 1-8-4-3-6-5-7-2
Spark Plug Type AC - MR43T/Champion - RV15YC4/NGK - BR6FS
Spark Plug Gap .035 In. (0.9 mm)
Timing (at Idle RPM)
3
8° BTDC
Preliminary Idle
Mixture
1-1/4 Turns
Thermostat 143° F (62° C)
1
Power Rated in Accordance with NMMA (National Marine Manufacturers’ Association) rating procedures.
2
Measured using an accurate service tachometer and Fuel Injection engine at operating temperature.
3
Timing must be set using a special procedure as outlined in the appropriate Service Manual. Timing cannot be properly set using
the conventional method.