do as I did with mine ...Take a short trim flight land and check your fuel level ....I already had a good idea of the fuel consumption rate because I test run the engine in the plane to set up the throttle down and throttle cut, mine ran for about 15min on the stock tank ...running it full open and then as if i were flying it throttle up and down ... O by the way I am running a OS 70 fs.....Hope this will help you...JW