Drove a FMG 678 ...engine was soo bad i was putting Gear oil in it EP 75 90 .. engine way under power for that type off forwarder ..i drove a timberjack 810b... JCB 3cx engine 90hp ...better engine... it needs 100hp + when U replace that lomp off scrap... ..helo from Ireland😉.
sadly the engine does not fire one of the cylinders every time, but your biggest issue will be the road it self. a few more runs, and the underside of the poor mini will touch the ground. you should really use a stack of wood, tow it witht he forwarder. it smooths the road, and you will be far more effective.