Suzuki DT40 idle problems

I have a Suzuki DT40 outboard on my skiff and I'm trying to prepare for this summer, but I can't get the engine to idle right. It ran fine the last time I used it last fall, but now it won't idle unless I'm giving it gas. I took the carb off and cleaned as much as I could. It sat over the winter and the fuel is from last fall so about 6 months old. I'm not sure if i need to do a carb rebuild or what my next steps should be. The only thing I've done is look at the spark plugs, sprayed some carb cleaner, and tried new fuel. I'm puzzled since the last time I used it it ran fine and nothing has been changed since. Spark plugs look good and it seems to run fine when I give it gas it just wants to die and dies at idle with no throttle. Anybody have any carb diagrams? Maybe I can do a more extensive carb cleaning. Any input would be appreciated, thank you.

Forgot to add the oil injection system has been removed. Another note, I let a friend use the boat last summer and I added oil to the fuel and told him all he needed to do was to fuel up before he went out to fish. He didn't fuel up and said the engine started smoking on his way back into the harbor. The engine seemed to run fine after that, but that was one of the last times before the end of the season last year.

Leaving mixed fuel in a carburetor over winter is a mistake.-------It is time to remove the carburetor for cleaning.------Not a big job and usually no parts needed.