Have you checked the operation with the guidebar and chain removed?
Remove guidebar and chain and run up saw (avoid contact with exposed moving parts, clutch etc). If you get a good flow of oil the problem may be with debris blocking the oil way in the guidebar. There will be a small hole in the side of the guidebar that lines up with the oiler outlet on saw, check it is clear and also remove any debris from the bottom of the guidebar groove. Blockages in the oilway will give the same symptoms as a faulty oiler (ie lack of oil to the chain). Cleaning the guidebar rail and oilway should be part of regular chinsaw maintenance.
I have also found that some oilers will only fully work when using proper sawchain oil.
Hope this is of help
Robin S, August 2008
