My 1986 John Deere 655 Diesel (16HP 4WD) small tractor has a leaf collection system with a Kawasaki Model FA210D 5.2HP Motor. Ran carb 3X through ultrasonic bath but still won't adjust. Anyone know of an alternative small carb for this engine.  It's part number is Kawasaki 15001-2541. Thank you in advance.