I agree with sigflyer that the 500cc tank is way too small! I am running a saito 182 twin on YS 20/20 Wildcat and its good for 7 - 8 minutes max , unless I want to putt around at 1/4 throttle! After 3 deadsticks I followed suit and installed a 24 oz. as sigflyer did. Now I can go 10 minutes without worrying if its going to quit the next time I go vertical! While the twin doesn't have the power the 180 single does, it sure sounds sweet on those low flybys! Check out my website http://www.quiknet.com/~pheller (click on Airplanes 4) to see the special shaft extension Dave McAllister of Mac's Mufflers made so I could fit the twin in the cowl - also helped with the balance --- NO LEAD!