I have a 1993 B7100 HST 4x4 with a FEL. The FEL seems very weak when lifting up the boom arms. I was lifting my finish mower off of a trailer the other day, and it seemed like it took all it had to lift it. I would think it would be stronger, but I might be wrong. Any help on what might be wrong would be appreciated. Thanks.
A B7100 should be able to pick up about 595 pounds max.
Were you at 3/4 throttle or more? Checked flid levels? What does the manufacturer say the mower weighs?
According to the Kubota website a 48" finish mower weighs 450 pounds and that may not include the driveshaft. Another brand may weigh more. Add 20 pounds of dirt and a driveshaft and you are getting near capacity.
I assume you were using a chain. The further from the tractor the chain is the less it will pick up.