Are you the lead developer and owner of that project?
Project like this which has a leading person that doesn't have time for it most likely isn't going to be successful. If you don't have time for that project you have been working with I suggest you to take a rest for now and get back to it when you are ready. Anyway, what are you offering for the people that will be interested working on it?
I have no time for promotion by myself, I'm not an expert in promotion, so I'm looking for a specialist. Everyone must do their job in which he is the best.
I understand that part that you can no longer be part of the promotion but at least have time for it.
In that case, if you are still looking for it, there are various marketing teams that are offering their service on
Services. Just include on how much you are going to pay them or negotiate with them.