My Back Hoe will lift the machine if I keep the bucket about 5' from the pivot point. Thank God for that, as I have buried the thing in muddy clay up to the axles. If the BH dipper and bucket curl had another 20% that would be just perfect for the weight of the machine.
I really think someone was sleeping at the Kubota USA assembly plant when it came time to set the hydraulic pressures on the machine. I think my machine went out of the factory with whatever the pumps relief valves were set from Kubota's hydraulic pump sub-supplier.
Regarding the loader Kubota's own specs and your photos and statements regarding the loader, the roll back force on my loader is a joke compared to what it should be. As weak or weaker as any agricultural machine I ever used relative to the size of the L39's 6' wide bucket!
Once this is corrected, I think I will get a lot of use out of this machine. After the first service, it will be moved from the 5-acre property we have just sold to the 17-acre future home/farm we will be establishing over the next few years. There is already a barn on this property, where horses are boarded, so the poor L39 will have to sit under a Tarp till I get a tractor shed built.
Lots of room and things to do (Rocks, Holes Trees, Roads) with the L39 there.