Had my JD 318 set up with rear PTO and 48-inch shaft drive tiller. Rear PTO, clutch, and tiller worked super, lots of power but tiller was too big for the 318. Moved the clutch, rear PTO, and tiller to my JD 430 and now the tiller seems to spin at about 2/3 the speed as when on the JD 318. The JD 430 runs strong, but the tiller runs weak. Any ideas why or suggestions?