Need help on my 1979 Johnson Motor

I need help. I have a 79" johnson engine with 70 horse. The engine spit a lot of gas thru the carburetor.

Has the engine been sitting up for a while or do you use it on a regular basis? Does it run at all? Does it miss out? Spitting gas back thru the carbs could be caused by a damaged needle, seat or float in the carbs. It could also be caused by damaged reed valves. Here is a good info website www.maxrules.com

Thank you for your reply, every info helps.
I use it on a regular basis, but after the trip from Texoma 3 weeks ago I stop. It doesn't back fire at all but it doesn't want to go. What do u think? Could it be a major problem ?