1977 9.9 Johnson boat motor It runs good with the choke half way in Is it ok to run it like that?

it is not okay to run your motor like that your choke is what controls air to gas mix ratio on engine, what you will have to do is take your carb apart and clean. it is fairly easy you usually only have 3 bolts holding on your float bowl then you have your float inside and a few jets depending on model of carb, which you spin out and clean then you have your fuel adjustment and air adjustment usually on the side of carb pull them out and clean check your points on the adjustments if smooched in than you will need to replace, then clean your thoat of the carb and you choke butter fly and your problem should be fixed