Volvo Penta AQ151 User Manual

11
Trouble-shooting Scheme
Main switch open. Battery
discharged. Wires broken or
fuse blown.
Empty fuel tank, closed fuel cock,
clogged fuel filter.
Water or impurities in the fuel.
Faulty spark plugs.
Burned breaker points, moisture
in distributor and ignition leads.
Faulty electronic unit 251DOHC,
AQ171
Idling speed not adjusted properly.
Faulty tachometer.
Boat loaded abnormally.
Growth on boat bottom and
sterndrive.
Damaged propeller.
Clogged cooling water intake, oil
cooler (250, 251DOHC, AQ151,
AQ171) waterjackets. Damaged
impeller or thermostat. Too low
coolant level in expansion tank
Wrong fuel quality in relation to
timing
Toothed belt faulty or not adjusted
properly.
Engine
does not
start
Engine
stops
Engine does
not reach op-
erating speed
at full throttle
Engine runs
rough or vi-
brates abnor-
mally
Engine be-
comes abnor-
mally hot
Fault reason
X
X
X
XX
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

Volvo Penta AQ151 Specifications

General

Engine Type	Inline 4-cylinder
Compression Ratio	9.5:1
Cooling System	Freshwater cooling with heat exchanger
Displacement	2.5 liters
Bore x Stroke	96 mm x 86 mm
Fuel System	Carburetor
Power Output	107 kW (145 hp) at 5700 rpm