You will never know real throttle response till you try a bucket of pure race gas, with an ether oxygenate. It will only come with the high compression motor. It WILL drastically increase rebuilds, f or 2 stroke. Money, it dictates what you will realistically afford to race? I am sure a 144 on pump gas, and the way I seen you ride in some vids, you would do fine! The difference between the f and 2s, that higher rotational mass is heavier up top, and costs more money. You may get used to it, many have, and work around the valve train wear? What ever you do, stay away from the airport. And the last time I bought race gas, about a year ago? It was at 75 dollars for 5 gallons.