I don't think you are getting her hot enough. The expansion chamber/exhaust system must be at peak temperature and fully expanded in order to have the sled rip. I guess I can end this post with the question I should have started it with. Does it do it all the time or only just after start up.
Get her good and hot and see if it helps.
i HAVE 450 MILES ON MINE AND IT HAS A HUGE MIDRANGE HIT AND THE THROTTLE RESPONCE IS INSTINTAINOUS. MINE WAS ALSO A LITTLE BOGGY AT FIRST AND IT WAS BECAUSE THERE WAS TOO MUCH BELT DEFLECTION. AS YOU PUT MORE MILES ON IT IT WILL GET FASTER.
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