the separates or next to the electric box. Try cleaning then, Its just a filter that UN screws. You might want to rebuild the crab and clean the filters in them to. Your fuel selector valve can also be clogged. You might want to check the mix screws on the carbs to . You can do a simple check to see if the engines are flooding by removing the spark plug after running to see if they are wet. if so the mix screws on the carbs are off. I'm new to these boat ( bought my at the beginning of the summer) and have never worked on them. Its very easy to repair them. don't bring it to a shop you will over pay. i could be wrong tho but Dr Honda is very smart and he will help you out if I'm wrong. Did you do a compression test ? mine are at 130 psi and run srong but any thing under that you my think about a rebuild. The best on this is sbt.com or fullbore.com . you send them you engines and they send back a total rebuilt one . If you go to a shop they will want about 700-800 just for a top end rebuild. like i said the engines are very easy to pull and reinstall.