I have a gearing question....most guys at our track are running either an 11/63 or a 12/68. I'm about 100 lbs overweight. Tonight I tried a 12/70 and the kart was junk. I was topping out at about 6580 rpm. My question is...am I going to be way different on gearing being 100 lbs overweight or am I out to lunch and getting myself gear bound?