I have a Kubota 2650. It has been a great tractor. Recently, I am having troubles moving forward or reverse when pushing on the pedal. I can rev up the engine and use my backhoe but when I attempt to move the tractor I can only lightly push on the pedal and move it very slowly or it stalls. It was sporadic for a while and I sprayed WD40 on the safety on the seat and the plunger on the pedal but yesterday I went to load it on my trailer and it was continually stalling. Any solutions?