I just bought a Kubota BX2670 and had the rear hydraulic kit fitted. The kit provided 2 sets of rear outlets with controls that spring back to the centre. I want to vary the amount of flow to change the speed of a hydraulic motor on an attachment which also uses the PTO to turn a screw. The dealer did not know of a modification and told me to tie a rope onto the control leaver and put a return line in with tap to control flow. This seems ridiculous and I was hoping someone new a better method or if a detent controller was available to fit this tractor. Can I remove a spring and have variable control?