My Walkerized 372XP showed up today, and I am wondering what I need to know about maintenance that goes above and beyond stock saw maintenance. For example, I'm not seeing a spark arrestor screen on the dual exhaust outlets, but is there something inside the muffler I should be looking at after a few tanks of fuel? I know a lot of you guys have Powertuned or Walkerized saws, so I'd appreciate a little advice on how to keep my investment running at top form.