[Jaime]

Sorry, Trykemike. I haven't read this topic for months... :oops:

The equivalent to the mixture screw is the "pilot screw", #13 in the diagram. It enrichens the mixture when turning it out too. When it's located in the air filter side, it usually enrichens when turning in.

The first thing to do is choosing the proper main jet, as it causes the biggest impact on the mixture. The needle jet isn't used to be changed much, but in the GZ250 it's a need. The mixture screw, on the other hand, only affects the first 1/3 of throttle range.

The increase in performance is noticeable, but not astonishing. Anyway, I've "raced" a stock GZ250 and mine blowed it away, I had to wait for him at tiny throttle.