[SlowButSteady]

When you say that the motor got loud, did it sound like the exhaust got louder or was it more of a thumping/vibration? If it's the former then there may well be something wrong with the engine itself. If the latter, like others have said, it's probably a fouled prop, bad motor mount, bad cutlass bearing, or some combination of those.


BTW, I would look for a new mechanic if I were you.