No a 125 frame is too small to fit a 250 motor but with a cutting torch and a welder anything is possible.
Yes, you're good to go with it, they are the same part.
with a little snipping there should be no problem. if you don't mind doing a little hand work. it's possible because i slapped 1999 yz 250 plastics on my 1990 yz 125.
no it will not
NO
yz 125 use the same plastics from 1996 to 2001
NO
yes it can i have done it
yes it does fit but u mite have to get new motor mounts for it but that about it, it should mount rite up then
Yes the specs were the same for thoise years.
Anything from 1998 to 2005 should work
with new engine mounts probably but i dont think it would go right in