First of all never use regular oil like 3 in 1 or any other product. Only use Crosman pellgun oil, RWS oil or Gamo oil. The other oils have petroleum products in them an will ruin the o-rings over time.
Oil the moving joints. anywhere you have metal rubbing against metal.
The Crosman model 120 was made between 1952-1954. The has a fore arm pump and shot a .22 caliber pellet not a .177 common pellet. The .22 caliber pellet was loaded through the loading port at the rear of the barrel. .22 caliber pellets are still available through most sporting good stores. Actually it's a very nice rifle.
Replace pump / pitman arm
Most "PUMP" air guns use the for-arm (Forward Handle) to pump the air gun.
With your arm and a repair manual
left arm
An arm and a leg.
Two bolts and hoses. When fitting to KA /KB, the arm on the pump goes UNDER the cam. Later B6 engines the arm goes OVER the cam. If you put the early model over the cam you will break the arm when tightening the bolts, Chris
bec of long moment arm
The wrist and the shoulder can be considered attachment areas of the arm. The arm is attached to - the neck at the shoulder - the torso (chest, back) at the sides of the shoulder and the armpit - the hand at the wrist
The crease of the arm inside the elbow, the inner wrist, and the outside of the hand.
I believe it's with the electric fuel pump inside the fuel tank , and has a float attached to the arm
a body pump class is an arobic class that works your arm muscles and you can lose calories from about 600 in one hour! You can take body pump classes at your local gym!