how to stop the self bar oiler from leaking?

Are the oil feed holes on the bar clear, to check this hold the saw whilst running with the bar pointing at a log or cut surface as you accellerate the saw there should be a film of oil
building up on the target area.
If this is not the case then clear the bar oil feed holes.
Turn the saw upside down and look behind the clutch cover, on more modern or professional saws there is a screw visible with 3 to 4 marked points around it on the casing.
It is then simply a case of turning the screw back by degrees to lessen the oil flow, this would only occur on saws with a variable oil feed but most modern saws would have this facility.
Regards!

A.L.Bradshaw.
July 2006