Aka the 550XP? That remains to be seen I think but Randy himself commented on the insanity this saw put out. He has a hand filed square chisel chain on it in another vid and it was almost a full second faster thru the cant. He also hasn't touched the timing yet but in the past, moronic saws didn't take very well to that.
Best part for me is its still a strato saw.
No, the 2153 is a 346 in red...... it was the fastest 50cc he had built.