Dubro Vibration Reducing Motor Mount - 50 to 75 two strokesDu Bro's innovative motor mounts are very effective in reducing airframe vibration & greatly reduce fatigue on the entire airframe. They are a totally captive mount that cannot debond & break free. Looking at the exploded view, the spool is solidly bolted to the firewall. The elastomeric rides on the spool & the sleeve which bears the engine & surrounds the elastomeric. The outer rib of the elastomeric absorbs the initial torque loads of the engine