MAINTENANCE - 1B - 3
90-816462 2-695
Tune-Up Specifications
Model
MCM 3.0L
MCM 3.0LX
Propshaft Horsepower Ratings
(Kilowatts)
115 (86)
135 (101)
Number Of Cylinders
4
Displacement
181 CID (3.0L)
Bore/Stroke
4.00 in./3.60 in. (101.6/91.4 mm)
Compression Ratio
9.25:1
Compression Pressure
140 PSI (966 kPa)
Idle RPM (in Forward Gear)
650-700
Maximum RPM (at W.O.T.)
4200-4600
4400-4800
OIl Pressure (at 2000 RPM)
30-60 PSI (207-414 kPa)
Min. Oil Pressure (at Idle)
5 - 6-1/2 PSI (35-44 kPa)
Fuel (Pump) Pressure
12 Volt Negative (–) Ground
Min. Battery Cold
Cranking Amperes
375 cca / 475 mca / 90 Ah
Firing Order
1-3-4-2
Spark Plug Type
AC-MR43T
Champion RV15YC4
NGK BR6FS
AC-MR43LTS
Champion RS9YC
NGK BPR6EFS
Spark Plug Gap
.035 In. (0.9 mm)
Ti i
(
Idl RPM)
Breaker Points Ignition
8
°
BTDC
Timing (at Idle RPM)
DDIS Ignition
8
°
BTDC
Delco EST Ignition
1
°
BTDC (NOTE)
Preliminary Idle Mixture
1 -1/4 Turns
Thermostat
143
°
F (62
°
C)
Dwell
39
°
- 45
°
Breaker Point Gap
.016 in. (0.5 mm)
Breaker Point Spring Tension
20-27 oz. (567 - 765 g)
NOTE: Timing must be set using a special procedure as outlined in the appropriate Service Manual. Timing cannot
be properly set using the conventional method.
L.H. ROTATION FIRING ORDER
FRONT
50653
1-3-4-2
Engine Firing Order
Index