Hey Suit & Wayne,
Okay, so we have a new place to yack about JBB's! I don't think the JBB is the problem with that engine...... I never had good luck with idling the darn things(YS) They are great for transitioning and top end power but the three I had would never idle. I would be suspicious of the internal workings for it's pump mechanism. I adjusted and adjusted and never got it to work. I let "YS" owners try to get it running right but always ended up swearing at the motor! Glad you sent it in for service. Slap ANYTHING on that JBB and go have FUN flying it!! You're missing a great airplane when whatever motor is on it doesn't perform for you!
Terry