3.0L mercruiser

[cerveza fria]

My boat has been sitting for about 6 months with a 1/4 tank of gas in it. I started remodeling it in March but i had to put the project on the backburner because of my work schedule and my course load at LSU. I graduate next week and I will have alot more time on my hands to finish the project. I plan on changing all of the fuids and filters Tuesday and taking it to grand isle the following week. I know that I should have either drained the tank or put fuel stabalizer in it. What should i do before i crank it? Do i need to drain the tank completly, or will adding octane boost and fresh gas be ok??