Engine wonbt go over 2k rpms

"Hey guys new to the site and

"Hey guys new to the site and nice I may add. I have a 91' Merc 260hp 350 5.7L engine that was sitting for a couple of years. On land it started ok but had no problems running up the rpms. In the water or under a load I should say won't go over 2k rpms. I replaced the coil because it was arching did a full tune up, plugs, wires, cap and rotor. The carb looks ok, and she starts up ok. Any idears before I put a bullet in the engine?
Thanks in advance!!!"

"Timing correct? Carburetor i

"Timing correct? Carburetor is probably full of varnish from old fuel drying up. Liberally spray the throats with carb cleaner. Change the fuel pump filter and carb filter screen. Before reattaching the fuel line, make a mix of fresh (2 oz.)gas and (4 oz.)Sea Foam. Use a clean fuel line attached to a clean funnel and slowly pour it into the bowl thru the fuel line inlet while pumping the accellerator several times and then let it sit over night and see if it has disolved the varnish. Pour the rest of the Sea Foam in the fuel tank with no more than 10 gal. of fresh fuel. Rock the boat to mix. You did drain the old fuel before starting it? Do all of the above on a COLD engine. No change, rebuild the carb."

"Thanks Guy, timming is pretty

"Thanks Guy, timming is pretty much on the money so I'm assuming its the carb. Just going to send it out to get rebuilt or buy a new one.
Thanks,
J"