Similar to you I run 110 leaded in my two-strokes and 93 pump in my four strokes. The race gas for neither the octane or lead, just for jetting consistency and lack of deposits. The 110 leaded won't hurt anything without an O2 sensor or cat, but would probably just be a waste of money in the 4T. Might be in the 2T too, but since my 125 will do a lap and a half on what's in the float bowl, the cost is negligible. Race gas was also pretty much required when I raced karts and any alcohol content would fail the fuel testing. As has been discussed on here before you pretty much can't get pump without alcohol in it these days.