Hey guys i currently bought a bass boat with a late 80's 90HP johnson...ran fine, idled fine and really ran good in the upper RPMs. Well i took it out the other yesterday and it started right up and idles fine but when i give it throttle it sounds like the exhaust has gotten louder if that makes sense? and it dosent rev as quickly or smoothly..ive had it out all summer with 0 problems and now its kinda acting wierd. The first thing i noticed was the increase exhaust sound..atleast thats what it sounds like to me. anyone have any recommendations about where i should start to diagnose it? Thanks.