I have one 4*6 cheap band saw and I cur routinely 100 mm dia round aluminium and same size cast iron. Biggest pieces of structural steel and key stock I cur regularry is about 20 - 50 thick.
100% agree with Lew Merrick. Few more hard learned pointers
* This size blade hardly ever have low TPI, but that is not a huge problem if you adjust feed and use flood coolant.
* I buy quality blades and tighten them pretty hard. I think most of the people use too slack blade.
* Water emulssion coolant is messy and annoying, but pretty essential when material is thick or swarf has tendency to stick to blade. I ahve used pressurized air to remove swarf from the blade, works too.
* I have build a hydraulic slow decend to controll the drop more closely. Pretty essential on aluminium and thin wall sections.
I change the oil on the screw drive pretty often. it was originally filled with sand, crud and wok oil. Carreer of thsi saw would have been very short unless I cleanned it. Also bearing selas are not very good, and oil seeps out if the arm is left uppright......
My brother bought similar looking saw and gear box side V-belt pulley was assembled wrong way....

Who in right mind would fit the belt in the step pulley arragement and try to make it work. Might be worth of checkking if it looks wonky. Set screw was inside one V and covered with crud...pretty much dropps of after the set screw is removed.
You want to check thet the tooth space is not filled with swarf when blade exitst the billet. You also want to check that blade is pretty clean when it enters into billet.
Motor in my saw is something like 500 to 750 W and it does not heat at all. Even when it is used for hours. In priciple electric motor could get pretty hot if dimenssioning is marginal. Is it possible that the motor is faulty, wiring (startter/switch/capacitor) is faulty or something is binding?
Pekka