That what the above post stated only rules for the class is no strokers and no reeds.Tech requires looking in carb and running a dial caliper down spark plug hole. That's the great thing about the class no cheating because everything is legal except two things and their easy to check. Have you ever done a tech on a WKA engine cc heads, check bore, check carburetor, check stroke, check ports. Thats as bad as the clone class, it sucks. Plus the cost of a top WKA engine is even more to get max out of a stocker. You tell me guys wont go to Gary woltjer and spend the money to have the best stocker money can buy, HA HA don't kid yourself. That's what put the stock Yamaha out of business in the WKA and IKF to much money for a stock engine that makes 18 or 19 hp. This is why we now have lawnmower engines on karts called clones. If you don't like the word open then call them stock appearing hows that. With the same mentality I can say how can you have a modified engine series that has different RULES for every engine in the same class. This is a support class UAS will not want a bunch of tech work to do , they already have plenty with the modifieds. Besides no one has to run the Yamaha if they don't wont to. Just run your open engine and don't mess with the Yamaha. Keep the class cheap and hassle free, its just for fun anyway and to help get more karts to the track for a bigger turn out to the UAS event. Also give the open boys a little more track time if they want.