Greetings JFoy,
In reading the above part if your post I nited your comment about fel lifting ability as a disappointment. So you mention lifting with your forks only about 400 lbs.. is that with clampon forks or with real forks?
Let me say why this is important. The Kubota spec for your fel lift is 745 lbs which includes the bucket and any quick attach. So if your bucket is 150 lbs by itself thats already 20%. Then if you have a quick attach thats another 8 or 10% and then if its clamp on forks from landpride we're talkibg another 55 to 65 lbs depending on which size. And to make matters worse if you use clamp ons your pallet is considerably further away from the pins which further reduces your capacity.
I have a Massey gc1715 and its a scut too. My fork set weighs 110 pounds and my quick attach weighs 77 pounds (your q.a. may weigh less). So my forks and qa together are 187 pounds. Using your Kubota spec if you load your payload to the back of a real fork set you should be able to lift at minimum 500 to 550 pounds to full height and more than that to a 2 or 3 foot height and that is using your kubota specifications. Late last fall I tested my unit quite accurately. My lift spec is higher than yours but I was lifting more than the massey spec by a fair amount. My point is . . Kubota us good equipment. You should at least be avle to do your factory spec if you are ysing prooer technique and quality implements. 400 pound maximum lifting isn't close to factory spex . . so something in implement ir technique needs improvement imo. You should at least be able to do 30% more than you are . . if not more imo.