Enjoy huge power and performance with the compact 105HZ! These are the engines that precision aerobatic and 3D heli pilots have been waiting for! In order for 90-sized machines to nail huge maneuvers and hardcore, smackdown-style 3D it's all about power, and both the 105HZ and 105HZ-R have it in abundance. Displacement has been increased by 15%, while a huge venturi rams air into the carburetor, producing massive power. Plus, they fit in a .90-sized mounting pattern.