377 Mag Ect, Seacore 377 Mag Ect; 350/377 Mag And Seacore 350/377 Mag-Specifications; Fuel Requirements; Fuel Ratings - Mercury 350 MAG Manual

Section 4 - Specifications

Firing order
Minimum battery rating
Spark plug type
Spark plug gap
Emission control system

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
Displacement
Alternator amperage
RPM
Minimum oil pressure
Thermostat
Timing at idle
Firing order
Minimum battery rating
Spark plug type
Spark plug gap
Emission control system
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.
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Non‑DTS models
DTS models
Hot
Cold
WOT
Rev limiter
Idle in neutral
At 2000 RPM
At idle
Seawater‑cooled models
MPI models with Closed Cooling
Non‑DTS models
DTS models
1‑8‑4‑3‑6‑5‑7‑2
750 CCA, 950 MCA, 180 Ah
800 CCA, 1000 MCA, 190 Ah
AC Platinum (AC 41‑993)
AC Platinum (AC 41‑101)
1.5 mm (0.060 in.)
Electronic control (EC), heated oxygen sensor
(HO2S), catalyst
293 kW (320 hp)
6.2 L (377 cid)
72 A
65 A
4800–5200
5350
550
124 kPa (18 psi)
41 kPa (6 psi)
71° C (160° F)
77° C (170° F)
Not Adjustable
1‑8‑4‑3‑6‑5‑7‑2
750 CCA, 950 MCA, 180 Ah
800 CCA, 1000 MCA, 190 Ah
AC Platinum (AC 41‑993)
AC Platinum (AC 41‑101)
1.5 mm (0.060 in.)
Electronic control (EC), heated oxygen sensor
(HO2S), catalyst
90-8M0050539 MAY 2011
eng