exuast and engine problem

I have a 1987 150 evinrude outbpoard when I first fire boat it will idle and run but it doesn't want to take off when I throttle it will cut out and bog down for about 3 or 4 minutes and then it's just fine it does it every time I take it out but once it finishes doing that after a few minutes its just fine. And it also sounds like the exhaust is eacaping somewhere before it comes out of the propeller because I see the smoke and it sounds like it's louder than it's supposed to be anyone have any ideas of what these problems could be

sounds to me like you been using fuel with methanol and it has finally eaten up your gas hose inside and is clogging the carburetor. if so, won't be munch longer before you are out and it won't get you back to the landing. best be sure you got a strong charge on the trolling motor or a good paddle. I would start there. get a clean jar and pump gas thru the gas line into the jar. if you see rubbish, that's most likely the problem.

I will check that . i only use fuel stations that advertise no ethanol but who's know . Thanks for suggestion I will definitely check that though