5-7 liter hard starting when cold runs great after gets started

[turbot660]

I have 1984 Wellcraft with a 5.7 liter with Thunder Bolt ingintion when cold it wont start if I pull the coil wire off and turn the switch off it sparks after that I can get it to start but I have got it flooded by then and have to hold the throttle wide open and it starts then after that I can start it continuously until the next time it cools off I just got the boat from a guy that father owned it and took very good care of it but the son never put in the water for the past few years once I get it started it runs great and smooth as anything ps the guys brother did what he called a tune up with plugs and wires but I am not sure how far he went because I found new wires and plugs left in the boat but that is it