Don - the 640 should have an automatic oil pump on the gearbox, but it was the only non-super series engine with a top tank like that. It is possible someone swapped the gearbox from another model, or it is even possible that someone swapped a non-super series engine into an older gear drive saw frame.
Kevin - take the oil pump off, take it apart, and work the piston manually. You should be able to see the oil going down the inlet (green) and out the outlet (red). If the manual oiler works and the automatic oil pump does not the most likely problem is the piston is stuck. Sometimes just turning the adjuster screw a few turns clockwise will free them up, but removing the pump and working it manually is more positive.
T-zero - I have had a lot of 10 Series saws apart and I don't recall any with that type of wavy washer (spring washer). I have to believe someone substituted it in place of flat washer; metric fasteners use a lot of those wavy washer and SAE stuff does not.
nw saws - the 92 is a non-super series engine. That would be a more natural swap in a 640, or one of the 1-60/61/62/63 models if you want a gear drive, a 250 or one of the other front tank saws for a direct drive.
Mark
Kevin - take the oil pump off, take it apart, and work the piston manually. You should be able to see the oil going down the inlet (green) and out the outlet (red). If the manual oiler works and the automatic oil pump does not the most likely problem is the piston is stuck. Sometimes just turning the adjuster screw a few turns clockwise will free them up, but removing the pump and working it manually is more positive.
T-zero - I have had a lot of 10 Series saws apart and I don't recall any with that type of wavy washer (spring washer). I have to believe someone substituted it in place of flat washer; metric fasteners use a lot of those wavy washer and SAE stuff does not.
nw saws - the 92 is a non-super series engine. That would be a more natural swap in a 640, or one of the 1-60/61/62/63 models if you want a gear drive, a 250 or one of the other front tank saws for a direct drive.
Mark