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    2003 Mercury 90 HP 4-stroke - pulsating humming noise in neutral

    I've got a 2003 Mercury 90 HP 4-stroke that makes a very noticeable pulsating humming noise in neutral at idle (about 850 RPM). The sound is louder after running it hard for 5+ minutes. If I put it into forward (or reverse), still at idle speed, the sound goes away. There are 30 hours on the...
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    2003 Mercury 90HP 4-stroke crankcase oil level rises

    2003 Mercury 90HP 4-stroke on a Boston Whaler Montauk 170 (17'). 65 hours on the motor; run at 6,225-ft. elevation (Lake Tahoe); 13 3/4" x 15"P prop; 5800 RPM at WOT. <br /><br />Problem: crankcase oil level rises, oil gets thinner, turns a thin black color, and smells a little like gas. For...
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