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•FUEL SYSTEM •Cylinder head cover/Valve
ENGINE CANN’T START –Fault from engine cylinder head/valve may effect on the
capability of engine.
–Carburetor lacks oil –If engine is bad at slow speed, inspect whether ventilated
hole of crankcase gives out smoke. If it does, inspect
whether piston ring is blocked
–There is no fuel for the tank
–Filter is blocked
–Oil tube is blocked
–Ventilated hole of fuel tank cap is blocked Cylinder pressure is too low and difficult to start or is not
well at slow speed
–Oiil level is incorrect VALVE
–floater valve is clipped –Valve adjustment is not correct
–Engine fuel is too much –Valve is ablated or distorted
–Air cleaner is blocked –Valve timing is not correct
–Oil leaks out of carburetor –Valve spring is ruptured
–Fuel loses its efficience or is polluted –Valve spring is loosened
Mix gas is too thin Cylinder cap
–Float lever is too low –Air leaks out of cylinder cap gasket or the
gasket is damaged
–Oil leaks out of inlet valve –Cylinder cap is bended or ruptured
–Oil tube is blocked –Cyliner or piston is wrong
–Inlet oil tube of carburetor is blocked/bended Pressure is too high or engine is too hot or clashes
–Throttle valve is wrong –There is carbon deposit on cylinder head or piston
head.
–Fuel jet is blocked Cylinder head gives out smoke
–Carburetor is not adjusted well –Valve lever or valve pipe is abraded
Mix gas is too thick –Valve lever oil seal is damaged
–Choke is in open position –Cyliner, piston or piston ring is wrong
–Float lever is too high Cylinder head sounds abnormal noise
–Emulsification organ is blocked –Valve is not adjusted correctly
–Air cleaner filter core is blocked –Valve is clipped or valve spring is ruptured
–Gas leaks out of carburetor –Camshaft is abraded or damaged
–Carburetor is not adjusted correctly –Tiiming chain is too loose or abraded
Engine crushes out, difficult to starte and bad idle speed –Cam chain gears and sprocket are abraded
–Oil tube throttles -Timing chain tensioner is abraded or damaged
–Ignition is wrong –Rocker arm or rocker shaft is abraded
–Mix gas is too thin/thick(adjust mix ratio screw) –Cylinder or piston is wrong
–Fuel loses its efficience or is polluted Idle speed is not normal
–Air leaks out of inlet valve –Cylinder pressure is too low
–Idle speed is too slow –There is leakage on inlet valve
–Float lever is incorrect –Fuel supplement system is blocked
–Ventilated hole of fuel tank is blocked –Carburetor is wrong
–Oil pipe is blocked –Air cleaner is blocked