Took my boat to the shop to have carbs rebuilt on 2001 Johnson 150. I have had the boat since day 1, bought it new. Mechanic ask who has been in the carbs? I told him no one, because no ever has. He said well their are gaskets missing out of here and the screws have been tooled (showing where someone has taken them off). He said there are no gasket around the seats and a few other things. What gives. THe boat started this after taking it to where I bought it fora yearly tune up back years ago, do you think they could have messed with them to perhaps get me to come back and have then fixed. Boat was out of warranty when I took it to them. They were quick to diagnose the problem when I took it back to them to get an opinion on the bogging down. What do you think?