Are you sure the deck is not binding up? Kind of sounds like it has something that is pulling it down. I know my 2182 also with the 60" Haban will bog a bit when it gets a bunch of build up from wet grass.
If you think the carb is bad I have a good one in the box. Thought I had a bad carb but it turned out to be spark plug issues.
Other thoughts, fuel line, maybe the coil is going bad.
