Troubleshooting Guide - Shindaiwa 490 Owner's/Operator's Manual

Troubleshooting Guide

What To Check
Does the engine crank?
YES
Good compression?
YES
Does the tank contain fresh fuel
of the proper grade?
YES
Is fuel visible and moving in the
return line when priming?
YES
Is there spark at the spark plug
wire terminal?
YES
Check the spark plug.
What To Check
Is the engine overheating?
Engine is rough at all speeds.
May also have black smoke and/
or unburned fuel at the exhaust.
Engine is knocking.
ENGINE DOES NOT START
Possible Cause
NO
Faulty recoil starter.
Fluid in the crankcase.
Internal damage.
NO
Loose spark plug.
Excess wear on cylinder, piston, rings.
NO
Fuel incorrect, stale, or contaminated;
mixture incorrect.
Check for clogged fuel filter and/or vent.
NO
The ignition switch is in "O" (OFF) position.
NO
Shorted ignition ground.
Faulty ignition unit.
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.
LOW POWER OUTPUT
Possible Cause
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.
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.
Overheating condition.
Improper fuel.
Carbon deposits in the combustion chamber.
Remedy
Consult with an authorized servicing dealer.
Tighten and re-test.
Consult with an authorized servicing dealer.
Refill with fresh, clean unleaded gasoline with a pump
octane of 87 or higher mixed with 50:1 Shindaiwa
Premium 2-cycle mixing oil or with an equivalent high
quality 2-cycle mixing oil.
Replace fuel filter or vent as required. Restart.
Move switch to "I" (ON) position and restart.
Consult with an authorized servicing dealer.
Crank the engine with the plug removed, reinstall the
plug, and restart.
Clean and regap the plug to0.024"(0.6mm)-0.028"
(0.7mm). Restart.
Replace the plug with a NGK BPMR7A. Restart.
Remedy
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 50:1 Shindaiwa
Premium 2-cycle mixing oil or with an equivalent high
quality 2-cycle mixing oil.
Clean, repair or replace as necessary.
Consult with an authorized servicing dealer.
Clean or replace the air filter.
Tighten or replace the plug with a NGK BPMR7A.
Restart.
Repair or replace fuel filter and/or fuel line.
Refill with fresh fuel/oil mixture.
Consult with an authorized servicing dealer.
See above.
Check fuel octane rating; check for presence of
alcohol in the fuel. Refuel as necessary.
Consult with an authorized servicing dealer.
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