Fuel/Carb/Choke (???) problems on Nissan 30HP

Hi all,

I am new to trying to be my own boat mechanic so please bear with me. I have a 30hp Nissan 2 stroke, model NS30A3 on a pontoon boat. This was given to me by my Dad and I don't have much money to put into it so I've been trying to work on it myself.

I can put the "earmuffs" on the motor and it would run fine at home in the driveway. It did have issues starting but could usually get it going. When I take it out to the lake and put a load on it, it dies when I put it in gear. Then it takes a while for me to get it started back up, if I can at all. If I can ever get it going it doesn't seem to fully reach top RPM's every time (it does occasionally), even with full throttle. It sputters and surges.

I have replaced the primer bulb and hoses, replaced the sediment bowl with a temporary fuel filter and all the fuel lines to the fuel pump, replaced the fuel pump. I finally took the boat to a boat shop and explained the situation and they seemed to think the carb just needed cleaned better. They charged me to clean the carb and said it was running great. I took it out to the lake and it's the same issues. I do plan to take it back to them but with as much effort as I have put into fixing it now it's really frustrating.

I've had people tell me that it sounds like it's getting air in the fuel somehow but I'm not sure how. It does have an electric choke but I realized the rod (pictures attached) was either taken out or fell out. Could this be allowing air in? Or any other ideas? Any help would be greatly appreciated!
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Sounds like it's too lean. Yes, repair the choke and that should help starting a lot. Have the shop do a thorough re-cleaning, and you will likely be OK.

So the boat shop told me they THINK it's the coil to the power pack that is bad and that it's a $300 part to order. I looked for the part on Boats.net and it is unavailable. Does anyone else know of a part that would substitute for it? The parts I can find on amazon or ebay don't exactly match or say they will work with the NS30a3

There is no power pack. It's CD ignition. What method did they use to diagnose it? They are super reliable.
Boats.net is unfortunately not a Tohatsu dealer, so they don't have access to parts.
Given that you need to fix the choke, and it runs fine, except seems too lean, my money is still on the carburetor.
If indeed you do need a CD, they are available, but not cheap: