Troubleshooting Diagrams - ICS 680GC Service Manual

680GC SERVICE MANUAL
CHECK
The engine runs rough at
all speeds
A dirty air filter is the #1 reason for engine problems.
The engine is overheating.
Poor acceleration.
Uneven idle or engine
may "run away"
Diamond chain moves
at idle.
Excessive vibration.
POSSIBLE CAUSE
• Dirty or clogged air filter.
YES
• Water has been ingested.
• Loose or dirty spark plug.
• Operator is overworking
the saw.
• Carburetor mixture is too
lean.
YES
• Incorrect fuel/oil ratio.
• Flywheel fins are clogged.
• Air deflector is missing.
• Cylinder fins are clogged
• Dirty or clogged air filter.
• Clogged fuel filter.
YES
• Incorrect carburetor tune.
• Plugged tank breather.
• Blocked pulse tube.
• Air leak at intake boot,
cylinder gasket, or
YES
crankcase gasket.
• Faulty carburetor
diaphragm.
• Idle speed too high.
YES
• Broken clutch spring.
• Damaged shock absorber.
• Damaged or broken
YES
flywheel fins.
• Bent crankshaft.
© 2011 ICS- Blount Inc Specifications and pricing are subject to change without notice. P/N 525747 REV12Sep2012
25. DIAGRAMS
REPAIR
• Clean or replace the air filter.
• Inspect air intake sysetm for water.
• Inspect fuel system for water.
• Tighten, clean, or replace spark
plug.
• See Operator's Manual.
• See Carburetor Tuning section.
• See Saw Specifications section.
• Clean flywheel fins with wire
brush.
• See Starter Cover section.
• Clean cylinder fins.
• Clean or replace the air filter.
• Replace fuel filter.
• See Carburetor Tuning section.
• Repair or replace fuel tank
breather.
• Replace pulse tube.
• Inspect air intake boot.
• Pressure test crankcase.
• Replace carburetor.
• Adjust idle speed.
• Replace clutch spring.
• Replace shock absorbers
• Replace flywheel.
• Replace crankshaft.
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