I got a 1990 Mercury 80hp 2 stroke and it dont seem to be running right. Ill try my best to explain what the motor is doing, we got it out on the water and when you put the throttle down the motor will miss and kick the rpm's down or up. The motor is not running at the power it should have.

I have rebuilt the carbs, water pump, fuel pump, and ran some Quicksilver Power Tune through the motor. I am gonna get some spark plugs this week and see if that makes any difference. Anyone know what might be causing this problem?

Bad gas?

Find a place that sells Non-Oxygenated gas, motors don't like the ethanol.

Also make sure you have a clean fuel filter and water separator.

I completely forgot to put in the post that the motor hasnt been out on the water in about 4 years. That may help a little  

Air leak in the fuel lines?

sounds like bad/gummed up carbs. Are you sure you rebuilt them correctly?

yea I rebuilt them correctly and also cleaned them all with carb cleaner to get all the trash and anything else out.