Stihl MS 270 User Manual page 11

4.3 Chain Lubrication
In the event of trouble with the chain
lubrication system, check and
rectify other sources of faults before
disassembling the oil pump.
Condition
Chain receives no oil
Machine losing chain oil
Oil pump delivers insufficient oil
MS 270, MS 280
Cause
Oil tank empty
Oil inlet hole in guide bar is
blocked
Intake hose or pickup body
(strainer) clogged or intake hose
ruptured
Valve in oil tank blocked
Teeth on pump piston and/or worm
worn
Oil pump hoses blocked/damaged
Oil pump hoses porous/ruptured
Bore in pump housing worn
Pump piston worn
Oil pump hoses not installed
correctly/leaking/ruptured/blocked
Bore in pump housing worn
Remedy
Fill up with oil
Clean oil inlet hole
Wash intake hose and pickup body
(strainer) in fresh STIHL cleaner or
replace if necessary
Clean or replace valve
Install new oil pump and/or new
worm
Clean or replace hoses
Fit new hoses
Fit new oil pump
Fit new oil pump
Check correct installation of hoses
or clean/replace hoses
Fit new oil pump
11