Re: Is it possible to motorized my mountain bike?
Welcome to the forum.
The bike you pictured will not lend itself to an in-frame engine installation. First there is no room for the engine and second you'll have chain tension issues.
A rack mount,(engine over the rear wheel) either friction or chain drive will be your only viable options.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"