OS 55AX Piston removal
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The normal sequence is: 1) Remove cylinder head; 2) Remove rear cover; 3) Slide cylinder liner up, out of the case; 4) Move piston and rod assembly aft to take the rod off of the crank pin. The rod must slide aft on the wrist pin inside the piston. 5) Remove piston and rod assembly out through the top of the crankcase.
If there is burned-on fuel residue on the wrist pin, it may be difficult to get the rod off of the crank pin because it won't be able to slide aft. You can use a bit of heat from a heat gun to soften the fuel residue. If that doesn't work, an overnight soak in a crock pot full of antifreeze will usually soften the residue. If you use a crock pot in this manner, it is poisoned, and can never, ever, be used for food preparation.
If all else fails, you will have to cut the connecting rod to remove the piston/rod assembly. In that case, you need to make sure all metal shavings are removed from the engine and the bearings are clean.
If there is burned-on fuel residue on the wrist pin, it may be difficult to get the rod off of the crank pin because it won't be able to slide aft. You can use a bit of heat from a heat gun to soften the fuel residue. If that doesn't work, an overnight soak in a crock pot full of antifreeze will usually soften the residue. If you use a crock pot in this manner, it is poisoned, and can never, ever, be used for food preparation.
If all else fails, you will have to cut the connecting rod to remove the piston/rod assembly. In that case, you need to make sure all metal shavings are removed from the engine and the bearings are clean.