Evinrude E-tec 75 HP Service Manual page 334

TROUBLE CHECK CHART
OUTBOARD SURGES, RUNS ROUGH
OUTBOARD SURGES, RUNS ROUGH
OBSERVATION
1200 RPM and above S.A.F.E.
May be erratic or
inconsistent
Audible noise
T–6
POSSIBLE CAUSE
Incorrect, fouled, or worn spark
plugs
Water in fuel system
Contaminated or poor fuel
quality
Low or erratic fuel pressure
Air in fuel system
Fuel supply restricted
Restricted or leaking fuel
injector(s)
Faulty wiring, connections,
grounds, or CPS air gap
Low alternator output (55 V)
EMM program, timing, or
operation
Weak or erratic ignition
operation
Capacitor or 55 V circuit wiring
Restricted engine exhaust
Internal powerhead damage
Damaged gearcase
PROCEDURE
Access EMM fault codes
Replace spark plugs
Check water separator/fuel filter, sample fuel from
fuel return manifold test port
Check and replace fuel supply
Check pressure, refer to FUEL SYSTEM on
p. 155
Check for air in fuel supply manifold, refer to
FUEL SYSTEM on p. 155 (vapor separator
venting and fuel supply)
Check primer bulb, anti-siphon valve, and fuel
pick-up, check for fuel system air leaks
Check injectors, refer to FUEL SYSTEM on p. 155
Check all grounds, connections, and wiring.
Check CPS air gap.
Check voltage on 55 V circuit, refer to SYSTEM
ANALYSIS on p. 103 and ELECTRICAL AND
IGNITION on p. 123
Check EMM program and timing; check injector
coefficients; and monitor injector circuits and
ignition primary outputs
Check ignition, refer to SYSTEM ANALYSIS on
p. 103 and ELECTRICAL AND IGNITION on
p. 123
Check capacitor and 55 V circuit (white/red), refer
to SYSTEM ANALYSIS on p. 103 and
ELECTRICAL AND IGNITION on p. 123
Check and repair as needed
Check and repair as needed
Inspect gearcase and lubricate