Secret No. 8: Just because the motor won’t turn over doesn’t mean you’ve blown the engine.
Another common tale from both instructors is that of the “blown engine.” Inexperienced techs quickly diagnose it for one obvious reason — the engine is completely locked up and won’t turn over. The next steps see the tech drop the lower unit, set it in the corner and then start tearing apart a perfectly good engine, instead of simply trying first to turn the flywheel manually. “People take outboard powerheads off, saying they’re blown up, when actually they’ve got a lockedup gear case,” Hutt says. The problem can also happen on stern-drives and inboards. The motor is not necessarily blown; it simply won’t spin over because it’s coupled to the upper part of the frozen drive.