Hitachi CS 33EDP Service Manual page 7

Is chain oil discharged?
No
Insufficient chain oil in the oil tank
Clogged chain oil discharge port
Clogged guide bar oil feed port
Clogged oil filter
Poorly adjusted chain oil discharge amount
Defective oil pump
Use of high-viscosity chain oil
(in cold weather)
-6-
Supply oil.
Clean.
Clean.
Clean.
Adjust.
Replace.
Use genuine or
low-viscosity chain
oil (for winter use).