150 merc wont start

[steplift20]

1988 150 mercury o.b wont start, I havent used to boat to much this year only took her out 2 times and it ran great, went down and changed to impellor and when i tried to start her the motor turn and tried to start but would not, sounded like it was flooded took out the plugs, they where clean wiped them off and she started after a couple of triys but it wasnt right. went down last week tried to start her and she didnt start, im going to change the water sepperator and inline fuel filter but after that i dont know what to look for, any help would be great
thats what i get for painting the bottom after 15 years and buying her a knew trailer and fixing the cleats, i should have left her alone thanks guys