mine weighed 12 3/4 lbs with the RCS 1.4 and a 600 and 1100 batteries. Now i weigh 12 7/8 with the os-160 with the jett muffler 18 x 6 apc or mejzlik and a 2700 NMhi battery. i went bigger with the battery so i picked up some weight there even though i got rid of one battery and picked up a heavier prop....