2004 johnson 175
model j175glsrm
serial # 05049702
2004 stratos 285 magnum
25 tempest 3 blade
the past few times i have been out on the lake, i have noticed that as the day progresses, my holeshot becomes more and more sluggish. also, when it is cold, sometimes it makes a sneezing noise. the idle has been kinda rough as well. however, when i get up to speed, everything seems to be fine. 5500 rpm wot and doesnt seem to miss a beat. and the last fishing trip i went on, i went to trailer the boat and when i gassed it to pull it all the way on the trailer, it bogged down like it was about to die. i immediately let off the throttle and tried it again....same thing....i got off and winched the boat the rest of the way on the trailer. any ideas on what may be causing these multiple problems?