actually, some motorbikes have a carb ice problem, particularly older design engines on naked (ie unfaired) bikes, where the carbs tend to be a bit exposed to the wind. One particular bike that stands out is the Suzuki Bandit 600 and 1200, where if you were zooming along the motorway on a coldish, humid day, the carbs could freeze up completely, causing the engine to stop. The solution was to add electric heaters to the bottom of each carb chamber - if you look at a set of bandit carbs, they have a wire hanging off the bottom of each chamber for this.
If you're really, desparately interested, and ask nicely, I'll take a photo of mine for you
