It can be confusing, Brad. Basically, it goes like this;
2001- mid 2004, Triumph had regualr slotted mix screws hidden behind a pewter(?) slug, which was the Man's attempt at making the screws only accessible by a "qualified" mechanic.
Late 2004, Triumph, or whomever made the decision, switched to D-shaped screws. Again, an attempt to make it more difficult for the average Joe to monkey with.
So, on your 2008 SM you have D shaped mixture screws.
-brent
