Details: 1995 Mariner 60 HP on 18' pontoon boat.<br />The engine ran flawlessly on three consecutive weekends (1 hour increments) until Saturday.<br />Power loss 10 minutes into ride - rpm decreased to 3000 at WOT (normally 5500) BUT DID NOT DIE.<br /><br />I checked fuel filter, lines, and vent. Fuel pump is newly rebuilt. Gas was fresh.<br /><br />I removed the air silence and noticed an oily/milky substance coated on all three carbs... I cleaned them with carb cleaner. And then powered back up. Bottom carb (3rd) blows gas mixture that seems to collect on the other two carbs.<br /><br />At this point I don't know if the power loss is a result of the third carb, or I have multiple problems.<br /><br />Any help/suggestions would be greatly appreciated. Thank you in advance.