Poulan oiler
If I recall,correctly{sometimes I don't] it's an impulse driven pump located on the right lower foward portion of the little saw.You may have gotten a little piece of saw dust caught in the check valves and it's causing the problem.I have 2 of these little rascals,1 is disgused as a Dayton,the other is a Craftsman,but both are old enough to also have manual oilers.What I did was soak the pumps in WD-40{I buy it by the gal.}and blew them out,both directions ,with air,also clean the tank.After all this,fill the oil tank with diesel fuel,start the saw ,without the bar,and let it pump for a while.Worked for me.