A 1984 CT
110 seat DOES fit the CT
125, just not the other way around. The issues you'll run into are that the CT125 seat studs/bolts are spaced slightly further apart than the CT
110 ones, but the hinge on the CT
125 has oblong holes so it will accommodate the narrower spacing, while the hinge on the CT
110 will NOT fit the wide spacing of the CT125 seat unless you redrill it. The threads are different so you will use the CT110 hardware with the CT110 seat rather than the nice rubber isolated hardware that the CT125 has. The CT
110 seat is a little smaller overall, but doesn't look too out of place other than that
the angle is wrong and it's sloped forward which is probably the biggest problem with using it on the CT125. The CT110 seat doesn't latch, but it didn't on the CT110 either. I haven't ridden the CT125 with the CT110 seat installed, so can't comment on how it would hold up. It has rubber feet that are meant to make contact with the top of the fuel tank which is different on the CT125, so long term something could break there if it's not better supported, I don't know.
1984 CT110 seat on CT125

Note that I have a replacement hinge on my CT125, it's spring loaded so when I unlock the seat it pops up. It's kind of weak though so I'm able to set the seat flat despite the spring.
CT110 seat on 1984 CT110
Correct angle
