Offroad or FS roads in B.C.? Leagal..or not?

I'm seriously thinking of adding a 49cc kit to my bike; more of an emergency thing since a back injury (2 blown discs) can render my leg(s) useless at any time. Also, face it, it's a lot of fun to tool around on a motorized bike in the backwoods. Thing is, it's illegal to ride one on our public roadways, but does this extend to FS/logging roads and just plain trails in the mountains. My buddy has a Quad and he got nailed for driving without insurance/plates on the Harrison S FSR. What would happen with a motorized bike? I know, I can probably just do it and get away with it.. but what's the legality, just in case. ..Willy.