I recently purchased a Kubota KX71-3 mini excavator with 250 hours. It's been well kept and serviced at the Kubota dealer. I've been practicing with it to get a feel for its lifting capacity, as I do a lot of moving and setting stone. I grabbed a medium size stone, maybe 800-1000 pounds lifted it with no problem and experimented to see how far out I could reach out before the machine felt tippy. That never happened. Long before it would have felt unstable, the relief valve kicked in and slowly lowered the stone to the ground. A nice safety feature, I suppose" but I am used to being able to use a machine to its maximum capacity. I use my SVL75-2 track loader quite a bit on heavy stuff, and if I wanted to tip it, I certainly could. Should I have the relief pressure checked, or is what I experienced normal ?
I'm certainly not the final expert on this sort of thing, but I've never seen an excavator that relieved before it tipped. I'd think the relief should be checked.
that's odd. Usually an excavator will allow you to do stupid stuff readily.
Is that with the blade down lifting over the front? If so you've exceeded the lift capacity of the hydraulics and it hits the relief. If it does that lifting over the side there is something wrong, it should definitely tip first. A KX71 is a fairly small machine, lifting a 1000lb rock is probably pushing the limits unless you keep it pretty close.