Is a Yamaha PW 80 a 2 stoke or a 4 stroke?

it is a 2 stroke. a tip on Yamaha to tell if they are 2 strokes or 4 strokes is that a 2 stroke usually has less than 3 letters, and a 4 stroke usually has 3 letters before the engine size. for example, a "pw" 80 is a 2 stroke because it has less than 3 letters, and a "ttr" 125 is a 4 stroke because is has 3 letters. but in some cases a 4 stroke has 2 letters, like the "wr" 250