you had engaged 'Start-/Notleistung' (WarEmergencyPower)! You realy should use that only in emergency and than only for a very short time !
Fortunatly in the 109 it will be disabled automaticly after 1min use
But in the Ju87, you have to disable it manually, true. Actually , you dont need it for the start.
try to fly the 110 with around 1,1 ATA and around 2200 rpm in normal flight , there should be no stuttering than - as long you keep the temps in order.
Overrev is bad for an engine, but underrev too !