Lay the Poulan Micro XXV on its side, bar side down. Loosen the cap on the oil tank and remove it. Check the supply of oil in the tank. If it's less than half, refill the tank.
Pour the bar and chain oil into the tank slowly. Don't overfill the tank. Wipe up any spilled oil on the outside of the tank and engine to prevent accidental fires. Screw the oil cap back on.
Perform an oiling test. Fire the Poulan Micro XXV up and let it warm for a few minutes. Press and hold the throttle trigger down. Move the tip of the bar about 1/2 inch from a piece of fresh cut wood. Let go of the trigger, move the bar away and check the wood for a little covering of oil splatters.
Unscrew the bar clamp with the combination bar tool if no oil is present during the oiling test. Take the bar clamp, bar and chain off the saw. Clean out both oiler holes on the guide bar with the knife. Clean out both slots along the length of the bar with the knife. Refit the bar, chain and bar clamp and repeat the oiling test.
If you still see no oil, service the oil pump and clean the oil tank.