I drove an old Farmall 650 similar to those pictured,( this was when 806 Farmall's were new) it was around 65-70HP and had no trouble pulling a 14 foot heavy breaking disk. It had an air starter but was hydraulic over nitrogen air starter that you had to pump up the hydraulic oil to pressurize the nitrogen tank then hit the starter. If it didn't start, had to pump again for about 5 minutes. It wasn't too bad as far as comfort with a spring loaded seat with a shock absorber in the middle but my back was a lot stronger then. Other than no back rest, you just bounced along like Eddie Albert of Green Acres. It did not have power steering if IIRC and was still a bear to turn around as it took both hands plus it had a hand operated clutch so you had to have lots of room and coordination to run it without running over something or someone.