Attached is a 4th gear roll on dyno run from 1800 RPM to 6200 RPM at WOT on my FLHTCUI 1550 running the SE factory 1550 Satge I flash. The cursor (verticle line)is set at about 5000 RPM for data illustration. Note the plotted curves for front and rear knock retard. Bad stuff kicking in early and staying all the way to the top. This was taken Sept 1, 2002 Sunday. The next is after the cleanup.