Junglejim
Sorry for delay, not keeping up to date with posts, let me know your email and I can send you the workshop manual and owner’s manual. Lings at pretty good for finding spares to fit these, and I can give you a contact name, but new Honda parts are expensive!!
Alan, I’m not sure the carb you have shown will fit, but anyway, the problem would be that the F80 carb has got a governor.