I have a 16 ft. 1987 VIP with 85hp force I just got for $200. Boat is in great shape and was well maintained, but the boat hadn't been ran in 10 years, they just had to get rid of it. Before I did anything to the boat, I turned the key and the motor started right up. I have replaced the thermostat, plugs, fuel line on carbs, cleaned carb bowls out, new water pump, and replaced exhaust port plate and gaskets. Motor ran great in driveway on hose at 5500 to 6000 RPM. Put it on the water, gave it throttle and it bogged down. Would only get up to 2000-3000 RPM. Took the motor cap off, gave it full choke and the boat went right up on plane at 35 mph. Took the boat home and took the carbs apart and cleaned the lines out with carb cleaner. Going back on lake this weekend, but before I do, is there anything else I should look at?
Replace the fuel pump diaphram and give it a good decarb. Decarb instructions can be found in the FAQ at the beginning of the mainteance forums.
Also, under the number 3 carb there is a fitting that a hose from the intake cover connects to. This fitting has a tiny orifice and needs to be blown out with air or carb cleaner or oil will pool in the intake and causing bogging and hard starting.
There is also a thread in the FAQ titled Waking up a sleeping engine. You might read it also.