BN2 engine run-on

["Brashear, Jack, N" <JNBrashear@garverengineers.com>]

Hi All, my friend has only run his fresh BN2 engine a few times since a
total overhaul.  He claims to have 8.6 to 1 compression and he has done
his initial timing, carb settings, etc. up using a vacuum gauge.  He
started with 5 gallons of 87 octane fuel in the tank.  Anyway, he has a
run-on problem and would like to know what he can do to stop it short of
engaging the clutch while in gear.  Any feedback besides using an anti
run-on accessory would be appreciated.  Many Thanks!!
Jack