Agreed more info would be good. Your carb is old enough to have had the power valve ruptured from a backfire. Holley part #125-500 is an update for 1989 and older carbs. To test your power valve, while holding the large end, try to turn the small end. If it will turn, the valve is shot. If it won't turn, the valve still works. A blown power valve goes to full rich and the boat is barely drive-able, and will be leaving some black smoke.
Another possibility for running rich is a choke set too rich. Your choke should open fully within one minute of start-up.
TANDEM AXLE TRAILER PACKAGE
4 14x5.5 Series 07 Black Accent Wheels
4 ST205/75R14 Kenda tires mounted & balanced
Delivered within the U.S. for $549
TRAILER WHEELS, TIRES & ACCESSORIES
Aluminum, Steel & Galvanized Wheels, Kenda K550 & Gladiator QR25-TS Trailer
Chrome and Colored Lug Nuts, Spare Tire & Wheel, Spare Tire Carriers
Aluminum & Steel Fenders - single and dual axle
Please PM or email me for a price quote. Email: email@example.com