Hi there.
I was just given a daewoo mountain bike. I know, probably not the greatest in the the world. The left gear shifter lever was snapped off so i replaced that but then i found that no matter what way i set the thing that shifts the chain between the front cogs (front mech is it?), it wont go onto the first one. I screwed the lower limit screw right out but even at that the thing hits the frame of the bike and still wont shift onto the first cog.

Im thinking now that the bottom bracket is the problem and that the gogs are positioned too close to the frame. My problem is i have little experience of mountain bike mechanics and im not sure what can be done or how this came to be. Is this setup adjustible or is it more likely that the wrong parts have been used at some point?

I do a lot of dirt bike work and have plenty of tools so if anyone can point me in the right direction here ill get right to it.