I recently purchased a B2150 4WD, hydrostatic trans with a bucket loader on the front. Tractor runs well but has two different sized front tires. Both are 6x12 R tires but one is 22 inches tall and the other is about 24 inches tall. what is the correct diameter that should be on it? Not much luck looking up new tires with a kubota part number as they are over 5 hundred dollars. Any one know of a replacement tire that works for this tractor. I dont use the 4 wheel drive unless im stuck in 2 wheel drive and just noticed the difference in tire size.