Whats the easiest way to figure out if a plug is going bad? sounds kinda stupid but.............think I might have to run carb cleaner through my engine again did it last year and it unclogged my vaccum lines for carbon build up along with cleaning the internal too.

 

Pull them out and look at them. How many miles on them? If they are caked with carbon and other crap replace them and see if you notice any performance improvement.
Almost forgot, carb cleaner does not go through vacum lines.

 

oops.....through the air pump and the trottle body