Interesting that your tank and Fork locks are different. My '81 CT110 is all original from what I understand, but the key only works in the ignition and helmet/tank lock. I havn't pulled the lock to check codes, but did try and clean it out good, removing a lot of black crud. still won't budge, so come sprint I'll putt it and see if the codes match.

I don't really need the fork lock anyhow. I worry more about a couple guys throwing it in the back of a truck more than someone hot-wiring and stealing it. Not exactly going to be a fast joyride, plus most people wouldn't know how to shift right since it's not a standard 1 down/2 up pattern and there is no clutch.