I'm not up to speed on this rebuild. How much time is on this new topend? Have the rings sealed? That pfffftttt sound, I've had that, was always a rich condition at 1/8 throttle. Mine would clear up quick as the R's rose. Adjusting the needle did help.
About 5 hours on the top end. 180 psi. I am thinking it was just loaded up from all the kicking over I did when testing compression. Gonna hopefully ride it more than a few minutes this weekend, and see how it goes.