Need help! 98 Police Roadking

[2003flht]

Hey all

Just finished rebuilding my buddies top end on a 1998 Police Roadking.  New pistons and refreshed heads.  The bike runs and idles great, goes down the road like its ready to rip but when you hit about 1/4 throttle, it falls flat on its face.  seems like its hitting a rev limiter.  it has the stock ignition in it and the Magnelli fuel injection...

anybody got any ideas?   at a loss and ready to ride tomorrow!

thanks