Engine Malfunctions At Low Rpm; Engine Malfunctions At High Rpm - Husqvarna Z400 Series Service Manual

Engine Malfunctions at Low RPM

Diagnostic Checks
Is air cleaner clogged?
Is choke adjusted
properly?
Is the engine oil and
gasoline to correct
levels?
Is governor set
correctly?
Is timing gear aligned
correctly?
Is there excessive
carbon buildup in
combustion chamber?
Z400 Series
Results
YES: Clean or replace
air cleaner as
necessary.
NO: Go to next check.
YES: Go to next check.
NO: Adjust choke. See
"Check and Adjust
Choke Cable" on
page 4-5.
YES: Go to next check.
NO: Fill gasoline and
oil to correct
levels. See
"Machine
Specifications" on
page 2-4.
YES: Go to next check.
NO: See authorized
Husqvarna dealer
for assistance.
YES: Go to next check.
NO: See authorized
Husqvarna dealer
for assistance.
YES: See authorized
Husqvarna dealer
for assistance.
NO: Checks complete.

Engine Malfunctions at High RPM

Diagnostic Checks
Is air cleaner clogged?
Is the engine oil and
gasoline to correct
levels?
Are fuel lines clear of
obstructions with
sufficient fuel flow?
Is choke adjusted
properly?
Is governor set
correctly?
Is timing gear aligned
correctly?
Is there excessive
carbon buildup in
combustion chamber?
5-21
REPAIR
Results
YES: Clean or replace
air cleaner as
necessary.
NO: Go to next check.
YES: Go to next check.
NO: Fill gasoline and
oil to correct
levels. See
"Machine
Specifications" on
page 2-4.
YES: Go to next check.
NO: Adjust fuel lines as
necessary.
NO: Check fuel filter
and fuel pump for
contamination
buildup.
YES: Go to next check.
NO: Adjust choke. See
"Check and Adjust
Choke Cable" on
page 4-5.
YES: Go to next check.
NO: See authorized
Husqvarna dealer
for assistance.
YES: Go to next check.
NO: See authorized
Husqvarna dealer
for assistance.
YES: See authorized
Husqvarna dealer
for assistance.
NO: Checks complete.