1985 Mercury 1150 crank

[USMC_2]

I have not turned the motor over since I've owned the boat (4 weeks). I got everything done that it needed (steering cable, replaced fiberglass, etc.). I bought two new batteries, cleaned/replaced all connections. Turned key and the starter hit the flywheel and tried to turn it, but nothing. The boat is in neutral and the sparkplugs are pulled and shot the pistons with Marvel Mystery Oil and PB catalyst. I tried taking a breaker bar to the crankshaft nut in the middle of the flywheel after I soaked the . I tugged and hammered and still the flywheel won't budge. I'm afraid the motor is siezed since it hasn't been run in three years. Is there something obvious I'm missing, or is it pretty much a dead indian? Thanks

[AMD Rules]

Try removing the lower unit, to see if it may be the culprit.

If it still won't budge, pop the side inspection covers off to look at the piston skirts/rings.