Some cylinder mowers are deliberately designed to have the drum drive clutch slipping all the time, so you can control the speed along the ground by adjusting the clutch. The Scott Bonnar 45 is of this type: you would rarely operate it with the clutch fully engaged. However mowers that use a V belt as a clutch, seldom work this way: it would wear out the V belt.
Alroh is a very competent manufacturer, and is located close to you, so I suggest the first thing you should do is ask their service department whether the drum clutch is intended to slip during normal operation.
