Hisun HS700UTV-4, Maintenance Handbook

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GENERAL INFORMATION
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the engine has warmed up, piston expansion
reduces piston-to-cylinder clearance.
3. Knocking or rapping while decelerating—Usually caused by excessive rod bearing clearance.
4. Persistent knocking and vibration occurring every crankshaft rotation—Usually caused by
worn rod or main bearing(s). Can also be caused by broken piston rings or a damaged piston
pin.
5. Rapid on-off squeal—Compression leak around cylinder head gasket or spark plug(s).
6. Valve train noise—Check for the following:
a. Excessive valve clearance.
b. Worn or damaged camshaft.
c. Damaged camshaft.
d. Worn or damaged valve train components.
e. The valve hose hole is damaged
f. The valve sticks on the hose
g.
Broken valve spring.
h. Low oil pressure.
i. Clogged cylinder oil hole or oil passage.
ENGLNE LUBRICATION
Mis-operation of the engine lubrication system will cause the engine scrap.Check the lubrication oil
level and pressure of the engine.
HIGH OIL CONSUMPTION OR EXCESSIVE
Exhaust Smoke
1. Worn valve guides.
2. Worn valve guide seals.
3. Worn or damaged piston rings.
4. Incorrect piston ring installation.
Low Oil Pressure
1. Low oil level.
2. Worn or damaged oil pump.
3. Clogged oil strainer screen.
4. Clogged oil filter.
5. Internal oil leakage.
6. Oil relief valve stuck open.
7. Incorrect type of engine oil.
High Oil Pressure
1. The lubrication oil pressure valve is stuck and closed.
2. Clogged oil filter.