IDK 4 mills are QUICK!!
i dont see the bike ur looking at beating the 4mill unless u throw cubs or a 4mill . and those holeshots are gona slow u down!
the reason the YFZ is winning those 300ft is the torque a little longer race and the shee would track him down for sure!!
my YFZ ported head, Intake, exhaust, and exhaust cam is Fast out the hole but the shee catches up quick and passes me... the beauty of down south is that NO ONE says what they have so i really couldnt tell you what that YFZ should do...
hope this helped