Re: what year model is my 65 hp 4cyl
Must be a Red Stripe, fine motor they are!
Fond memories of my '71 650 on a 14' Fiberform.
Sounds like you need a new impeller or pump kit and when you service the carbs, you'd be money ahead to replace the float needles/seat, and also the floats themselves. It'll save you a lot of trouble in the future with leaky carbs.
Also it might not be a bad idea to replace the fuel pump gaskets/diaphragm, which tend to dry out and become weak after sitting for a long time.
These parts are available at the Merc dealer or aftermarket (Sierra parts etc). You won't need the carb "rebuild" kit, it's cheaper to buy the "packing kit" which has all the gaskets and soft goods you'll need, and pick up floats & needle/seat separately.
Look up parts on this site or my favorite,
http://www.boatfix.com/searchsierra.asp /
http://www.boatfix.com/mercobappguides.asp
Cheers.........ed