20 hp mercury super 200

alright I'm fixing up my fourteen foot john boat and I'm having the motor problems. first off its a early eighties merc. 20 hp. i put a new lower unit in it last year and greased everything up, but what my problem is every time i start it up it has to be choked no matter if i start it for the first time or if it has been running for twenty min. and i need to start it back up. and my second problem is when i go to idle down to switch gears it likes to die or when i idle down in general not just to switch gears. i switched all the hoses and spark plugs. if someone could help me out i would appreciate it. i think it may be a carb problem with the jets but I'm not sure.

I have a 1979 20 Merc & they're great motors.

I would rebuild the carb & fuel pump,pretty easy.You should be good to go than.

yea thats what i thought i should do im just trying to get some input thanks and i agree when it gets up and goes its fast for its size

I had a 25 merc at one time and I had this same problem. You pulled the choke to start and would go full out and will sometimes die off or cut out and if you slow down it tends to shut off. It is probibly your carbs. What I did was get i got fuel system cleaner and stabilizer and someone informed me to run the motor a few times on premium gas to help clear out the gunk and crap that may be in the carbs. I did that and that motor started up instantly after I did that.