Has the engine been tilted or run while tipped over or is the oil level to high (Overfilled)?
Fuel pump has three lines:
Gas tank to pump
Pump to carb
Pump to breather valve chamber cover (Source of vacuum to run the pump)
No, you will need to split the case to take the rod bolts off to slide the piston out.
Do you have oil coming out of the breather tube that goes up into the bottom of the air cleaner? See if your air cleaner is soaked. Could be blow by from worn rings. You may not need to replace the piston if the cylinders are within specs. You might get away with honing the cylinder and replacing the rings.
No oil coming out of breather tube under carb, just a **** of a lot coming out of oil filler tube to fuel pump. Spark plug doesn't look to bad either. Crankcase reed valve in one piece,Maybe I'll try the restore stuff before I tear in down.