'83 140hp Evinrude Problem

[90Evinrude]

i have a 83 140hp evinrude that will not open up at full thottle unless u push the choke in also this can be only done for a little bit and after about 2 min pushing the choke doesn't do anything.. i have cleaned the carbs 3 times and rebuilt them once i also cleaned and rebuilt the fuel pump.. what im i over looking or what else can be done..................also the rectifier is getting very hot and looks to be leaking some brown sticky substance but it doesnt seem to be affecting the motor should i replace it ....and finally what is the correct gapping on the spark plugs for this 83 140hp eviunrude