Cold Start

[evinrude20]

Hi there, last year I got my evinrude 20hp all fixed and it ran great. All throughout the summer it would start cold on the first or second pull and idle nice and smooth. Once the weather got cold int eh fall, it was a bit harder. This summer, I put it in the water, and it took about 20 pulls to get it to life, and wont idle low without stalling unless it runs for about 2 mins at higher rpms. Any ideas as to what may have chnged since last year? I suspect it may need new plugs? or is this a carb issue.... thanks alot.
Evinrude 20