60 hp yamaha wont get on plane

[flatsrabbit86]

Hello I'm robert I have a 17' sea chaser with a 60 yamaha on it. It is a 2004 never had any problems prior. The problem is that it wont go over 4000 rpms and get on plane. I beleive it is a fuel problem but not sure, I have took carbs apart they are in great shape I cleaned them anyway. I found little bit of water in separator, so I replaced that. Motor runs good in drive way but not under load. Any help would be nice thankyou.