Yes 125 cc doesn't sound too good Norm for a slasher, you would think it would only be good under light load cutting.
Looked up a comparison , a rough comparison.
Feature 125cc Victa 160cc Victa
Displacement ~125cc ~160cc
Typical HP (approx.) ~2.5–3 HP ~3.5–4.5 HP
Torque Lower Higher
Blade Handling Lighter blades / small mowers Heavy blades / slashers
Cooling / Load Design Lighter use Designed for higher resistance
Cheers
Max.
