Is it a Bosch or Valeo? I'm betting Valeo. I'm guessing its nothing under the front cover... but Smoking is bad, regardless. Dont let the smoke out
By "hard to start" do you mean it cranks just fine but the bike doesnt start, or it cranks badly, kinda half-assed, or doesnt respond to starter button very well...
Most starters will last seemingly forever, until one day it just goes kaput. Feels like usually one or two per bike lifetime, at least. That would be roughly one starter for every 50-100K miles, but I'm pulling these numbers straight out of my ass.
Do you have a known good starter you could swap out to check it?