Yingang YG125-30A, Руководство по обслуживанию

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YG125-30A Maintenance Manual Cylinder Head, Cylinder and Piston
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Troubleshooting

Low cylinder pressure
1. Valve:
-- Incorrect valve clearance adjusted;
-- Valve ablated or bent;
-- Valve sealing failure;
-- Incorrect valve timing;
-- Valve spring damaged.
2. Cylinder head:
-- Spark plug sealing failure;
-- Cylinder head gasket leaked or damaged;
-- Cylinder head cracked or blistered.
3. Cylinder and piston:
-- Piston ring clearance too big or cracked;
-- Piston cracked or damaged;
-- Cylinder / piston ring worn.

Black smoke from exhaust
1. Valve guide worn;
2. Oil shield leaked or damaged;
3. Cylinder / piston / piston ring worn;
4. Piston ring clearance too big;
5. Piston ring incorrectly installed;
6.
Piston or cylinder wall scratched or scuffed.
●
Excessive noise
1. Incorrect valve adjustment;
2. Valve jammed or valve spring broken;
3. Camshaft worn or damaged;
4. Timing chain too long, worn or damaged;
5. Timing chain tensioned failure;
6. Timing driven sprocket worn;
7. Cylinder / piston worn;
8. Rocker arm / Rocker-arm shaft worn;
9. Piston pin bore / piston pin worn.

Overheat / knocking (cylinder pressure too high)
1. Too much carbon deposited in combustion
chamber.
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