I agree. 90# on an air wrench would be good for almost nothing...."here". Maybe they use that setting for work in cuckoo clock factories or something like that....not farm shops.

As for the original poster's performance problem....are you 100% sure (make that 101%!) that the reversing button is/can go full travel? Whenever it's not in it's full position, it blocks or diverts air. I've often found that, even w/the good IR guns, that if you didn't quite get the reversing button pushed all the way (either way) it will have very little power.