All rite Merc Guys

I have an 82 model Merc 200HP and a parts motor that is a 92 model 150hp. Some of the electronics are the same so I kept the 92 for a parts motor. I got a needle and seat in the 82 that is giving me fits flooding out on idle but if I get it on plane it will clear out and run.
Couple of questions:
1) will the needle and seats interchange from the 92 to the 82?
2) when I looked up the part number for the 200 on the needle and seat it offered 2 different ones, gives an option if the motor is a WH-3A/11, what is this and how do I know if that is what I have?

The serial # is the key to what options, if any your motor has. Both SN's will tell you alot about each, and then what parts, if any are interchangable. I've seen a post or two by a boat mechanic on here but he doesn't post much. A visit to a repair shop may point you in the right direction, one of the techs might answer all your questions as well.

I personally would not use an old needle and seat even if it were the right one. The neoprene tip goes bad and will just cause the same problem you're already having. Get the model number and serial number off your mark and order online from crowleymarine.com or marineengine.com or iboats.com and it will usually be at your door in 3 business days. They're cheap.
JMO,
JBJ

The WH number is the number of the carb, and the early type will not interchange with newer style of carb. I would recomend taking your serial number and the number off the carb and get a rebuild kit, not just a gasket kit, and replace the float in that carb, I have seen floats that have gas in them and cause trouble at idle but when running flat out you really can't pour enough gas in these things. Rebuild/ replace it all, needle, seat, float and all gaskets and see if that doesn't take care of your problem