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September 10, 2021 at 9:06 am
#246440
I have a mix of model 100 and J-xx; they both have (close to) the same crankcase and jug.
In all cases but one, the cast iron rings were rusted to the bore. Multiple recurring applications of solvent (CLR and WD-40/PB Blaster) and heat have worked for me.
Heat the jug slowly. Once you have it unseized, dismantle the crankcase (you may need heat etc for the bolts), clean all components and then hone the bore. Try to get the ring groove clean without removing the ring.
The one case I failed, it was because I was trying to treat a seized piston when in fact I had a seized driveshaft/lower unit — so maybe you need to check that first.