Troubleshooting guide – Shindaiwa 81644 User Manual
Page 18
18
Troubleshooting Guide
ENGINE DOES NOT START
Does the engine crank?
Faulty recoil starter.
Fluid in the crankcase.
Internal damage.
Consult with an authorized servicing dealer.
NO
Good compression?
Loose spark plug.
Excess wear on cylinder, piston, rings.
Tighten and re-test.
Consult with an authorized servicing dealer.
NO
YES
Does the tank contain
fresh fuel of the proper
grade?
Refill with fresh, clean unleaded gasoline with
a pump octane of 87 or higher mixed with
a 2-cycle air cooled mixing oil that meets or
exceeds ISO-L-EGD and/or JASO FC classified
oils at 50:1 gasoline/oil ratio.
Fuel incorrect, stale or contaminated;
mixture incorrect.
NO
YES
Is fuel visible and moving
in the return line when
priming?
Check for clogged fuel filter and/or vent.
Priming pump not functioning properly.
Replace fuel filter or vent as required; restart.
Consult with an authorized servicing dealer.
NO
Is there spark at the spark
plug wire terminal?
The ignition switch is in “O” (OFF)
position.
Shorted ignition ground.
Faulty ignition unit.
Move switch to “I” (ON) position and restart.
Consult with an authorized servicing dealer.
NO
YES
YES
Check the spark plug.
If the plug is wet, excess fuel may be in
the cylinder.
The plug is fouled or improperly gapped.
The plug is damaged internally or of the
wrong size.
Crank the engine with the plug removed,
reinstall the plug and restart.
Clean and regap the plug to 0.024 - 0.028
inch (0.6 - 0.7 mm). Restart.
Replace the plug with an NGK BPMR6A or
equivalent resistor type spark plug of the
correct heat range. Set spark plug electrode
gap to 0.024 - 0.028 inch (0.6 - 0.7 mm).
YES
What To Check
Possible Cause
Remedy
LOW POWER OUTPUT
Is the engine overheating?
Operator is overworking the unit.
Carburetor mixture is too lean.
Improper fuel ratio.
Fan, fan cover, cylinder fins dirty or
damaged.
Carbon deposits on the piston or in
the muffler.
Shorten trimmer line. Cut at a slower rate.
Consult with an authorized servicing dealer.
Refill with fresh, clean unleaded gasoline with
a pump octane of 87 or higher mixed with
a 2-cycle air cooled mixing oil that meets or
exceeds ISO-L-EGD and/or JASO FC classified
oils at 50:1 gasoline/oil ratio.
Clean, repair or replace as necessary.
Consult with an authorized servicing dealer.
Possible Cause
Remedy
Engine is rough at all
speeds. May also have
black smoke and/or
unburned fuel at the
exhaust.
Clogged air cleaner element.
Loose or damaged spark plug.
Air leakage or clogged fuel line.
Water in the fuel.
Piston seizure
Faulty carburetor and/or diaphragm.
Service the air cleaner element.
Tighten or replace.
Repair or replace filter and/or fuel line.
Replace the fuel. See page 10.
Consult with an authorized servicing dealer.
Engine is knocking.
Oveheating condition.
Improper fuel.
Carbon deposits in the combustion
chamber.
Check fuel octane rating; check for presence of
alcohol in the fuel (page 10). Refuel as necessary.
Consult with an authorized servicing dealer.
What To Check
See above(Engine overheating).