I have a 10 year old RZ4219 and the smooth front tires won't hold air. They are a size 11x4.10-5. I see replacement tires and tubes in size 11x4.0-5. It's not quite the same size but close. Can I use the 4.0 tube instead of the 4.10 tube or should I just buy new tires or tire/wheel combos? The tires themselves are not dry rotted and I was hoping to just tube them to save some money but I can't find the exact tube size. Any suggestion what to get? Thanks