Agree- it may have a similar engine to the McCulloch, and to be honest the engine is probably the best bit of the McCulloch the rest is cr*p.
The problem you have sounds like "pilot error" and could happen to a £100 mower or a £1000 Hayter. I would check your oil level as it sounds as if it's been overfilled causing hydrostatic locking of the crankcase causing the symptoms you describe.
pleasant
September 2008