Originally Posted by
RETRO RC
As far as I know there where no performance changes made in regards to the cranks or sleaves they are still the gen 5.5.
the main changes where for durability with coated parts and a improved cooling head and carb.
But Mark from MM could shed a little more light on the subject.
From what I'm told, the sleeves have revised porting, the head has been lightened, and the carbs have been redesigned. The seals are a lot better now as well...
(haha... thats my attempt at early morning humor)