do not use the nylon engine mounts that come with the phoenix suhkoi or you will have engine vibration problems. i had a enya .50 cx on mine and i had to mount the engine on the extreme end of the mount for proper cowl fit and i had vibration problems. i later used a dave brown 4-stroke mount. i thought my sukhoi was a little heavy but my enya .50 had plenty of power to haul it around. warning!...do not do medium to slow tight turns with it ,...she'll snap out !, that's how i lost mine.