I don't envy you on that broken bolt. Nothing much to add other than some support. Been there myself recently. Good advise from all here. Left hand drill bits work very nice, torque in the right direction and builds a little heat while drilling. Before I drill I try to peck on the broken bolt with a hammer and drift.
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1996 -19' NV Flats 115 Mercury 4-stroke
1983 -20' Wellcraft Center Console 250 XS
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