Engine Runs Erratically; Engine Dies After Running - Husqvarna Z400 Series Service Manual

REPAIR

Engine Runs Erratically

Diagnostic Checks
Is air cleaner clogged?
Is spark plug
functioning properly?
See "Spark Test" on
page 6-19.
Is the spark plug gap to
specification?
Is spark plug seated
correctly?
Is water present in the
fuel?
Is fuel present in the
carburetor?
Does the engine
smooth out if partial
choke is applied?
Is carburetor operating
correctly?
Results
YES: Clean or replace
air cleaner as
necessary.
NO: Go to next check.
YES: Go to next check.
NO: Replace as
necessary.
YES: Go to next check.
NO: Adjust spark plug
gap to 0.03 in
(0.76 mm).
YES: Go to next check.
NO: Tighten spark plug
to 192 lb-in (22
N•m).
YES: Drain and refill gas
tank.
NO: Go to next check.
YES: Go to next check.
NO: Check for plugged
fuel lines, clogged
fuel filter, and
defective fuel
pump.
YES: Go to next check.
NO: See authorized
Husqvarna dealer
for assistance.
YES: Checks complete.
NO: See authorized
Husqvarna dealer
for assistance.

Engine Dies After Running

Diagnostic Checks
Does engine continue
to run after 20
seconds?
Does engine stop after
running under load?
5-20
Results
YES: Go to next check.
NO: Check clogged air
cleaner. Clean or
replace air cleaner
as necessary.
NO: Check choke. See
"Check and Adjust
Choke Cable" on
page 4-5.
NO: Check for fuel
contamination.
Replace fuel as
necessary.
YES: Check fuel lines
for kinks and
obstructions.
YES: Check for clogged
fuel filter and faulty
fuel pump.
NO: Checks complete.
Z400 Series