Mercury 350 MAG - 377 MAG ECT, Seacore 377 MAG ECT; 350;377 MAG and Seacore 350;377 MAG-Specifications; Fuel Requirements; Fuel Ratings

Section 4 - Specifications
Page 66 90-8M0050539 eng MAY 2011
Firing order
1‑8‑4‑3‑6‑5‑7‑2
Minimum battery rating
Non‑DTS models 750 CCA, 950 MCA, 180 Ah
DTS models 800 CCA, 1000 MCA, 190 Ah
Spark plug type
AC Platinum (AC 41‑993)
AC Platinum (AC 41‑101)
Spark plug gap
1.5 mm (0.060 in.)
Emission control system
Electronic control (EC), heated oxygen sensor
(HO2S), catalyst
377 MAG ECT, SeaCore 377 MAG ECT
NOTE: Performance specifications are obtained and corrected in accordance with SAE J1228/ISO 8665 Crankshaft Power.
All measurements are taken with the engine at normal operating temperature.
RPM range is measured using an accurate service tachometer with the engine at normal operating temperatures.
Oil pressure must be checked with the engine at normal operating temperature.
NOTE: Oil pressure specifications are for reference and may vary.
IMPORTANT: Do not mix spark plug types in an engine. All spark plugs should have the same part number.
Propshaft power
293 kW (320 hp)
Displacement
6.2 L (377 cid)
Alternator amperage
Hot 72 A
Cold 65 A
RPM
WOT 4800–5200
Rev limiter 5350
Idle in neutral 550
Minimum oil pressure
At 2000 RPM 124 kPa (18 psi)
At idle 41 kPa (6 psi)
Thermostat
Seawater‑cooled models 71° C (160° F)
MPI models with Closed Cooling 77° C (170° F)
Timing at idle
Not Adjustable
Firing order
1‑8‑4‑3‑6‑5‑7‑2
Minimum battery rating
Non‑DTS models 750 CCA, 950 MCA, 180 Ah
DTS models 800 CCA, 1000 MCA, 190 Ah
Spark plug type
AC Platinum (AC 41‑993)
AC Platinum (AC 41‑101)
Spark plug gap
1.5 mm (0.060 in.)
Emission control system
Electronic control (EC), heated oxygen sensor
(HO2S), catalyst
350/377 MAG and SeaCore 350/377 MAG—Specifications
Fuel Requirements
IMPORTANT: Use of improper gasoline can damage your engine. Engine damage resulting from the use of improper
gasoline is considered misuse of the engine and any resulting damage will not be covered under the limited warranty.
Fuel Ratings
Mercury MerCruiser engines will operate satisfactorily when using a major brand of unleaded gasoline meeting the following
specifications:
USA and Canada—having a posted pump Octane Rating of 87 (R+M)/2 minimum. Premium gasoline 92 (R+M)/2 Octane is also
acceptable. Do not use leaded gasoline.