Robin America EH63, Service Manual

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Phenomenon Possible causes Remedy
1. Low
compression
1) Loosen spark plug Retighten or replace gasket
2) Cylinder head gasket leakage Retighten or replace gasket
3) Piston ring(s) seizure or wear Replace
4) Piston or cylinder wear Repair or replace
5) Incorrect valve and seat contact Repair or replace
6) Valve stem seizure Repair or replace
7) Improper valve clearance Adjust
2. Ignition
system
malfunction
1) Spark plug faulty Replace
2) Ignition coil faulty Replace
3) Improper air gap between ignition coil and flywheel Adjust
4) Magneto demagnetization Replace
3. Fuel system
malfunction
1) Carburetor clogged Disassembly and clean
2) Improper fuel pump operation Disassembly and clean
3) Fuel strainer or fuel hose clogged Clean or replace
4) Air mixing into fuel lines Check and adjust connecting portion
5) Improper gasoline or water infiltration Replace
4. Low intake air
volume
1) Air cleaner clogged Clean or replace
2) Throttle valve faulty Repair or replace
9-3 INSUFFICIENT OUTPUT
9-4 OVERHEAT
Phenomenon Possible causes Remedy
Overheating
1) Cooling air flow obstructed at inlet or cylinder baffle
portion
Clean
2) Improper engine oil Replace
3) Lean air/fuel mixture Check and adjust carburetor
4) Excessive back pressure of exhaust system Check, clean or replace
5) Over-load Change to rated load