Ok, I think I just realized that I have a California model TW200 '87 but I purchased a non-California gas tank. Can I still make it work? I don't plan on getting emission inspection for the bike. What mods do I need to do for everything to operate?
While technically illegal the non-CA tank should work fine. Gas tank will just vent to atmosphere rather than through evaporative canister located on front frame tube. Canister could also be removed and carb's vent line left to vent atmospherically.
California makes a big deal out of attempts to limit gasoline fumes from escaping but in reality the locks on TW gas caps are not sealed units and fumes do escape despite the separate evaporative canister. So don't feel guilty for polluting more than any other TW.