9.9 4 stroke carb storage issues (ongoing)

I've got a 1988 9.9 4 stroke on my sailboat and every year, like clockwork, I've got to pull the carb apart and clean out the idle jet and circuit. I've tried completely draining it, running it out of fuel, leaving fuel in it with a heavy dose of stabilizer, even starting it up in the middle of winter here in the NE, and nothing I've done or can think of solves this annoying aggravation. I'm thinking of running marvel mystery oil though it next fall and "pickling" it to see if that does anything. Any one else have these issues? Once its done, the motor runs great for the rest of the summer until the following spring's startup.

I just started it up last week after sitting for 4 months without running and after 5 minutes, the yearly symptons started all over.

Thanks

MikeL

[boats.net]

That usually works, when you drain the carb by using drain screw on bowl of carb, tilt motor up and down to get all the gas from fuel pump and hoses drained. It may draining down and putting gas back into carb.