Help With My1992 115 Merc. HEATING AND SMOKING

HI,
i have a 1992 mercury 115 4 cyl 2+2.I'm having a couple of issues i cant figure out .
#1 after running the motor 5-10 minutes high rpm heat sensor alarm comes on.slow down to idle goes off.i have a strong steady pee.Ive changed the impeller.while the alarm is on Ive disconnected the heating sensor the alarm goes off.
#2 the motor sounds different than when it was running with no problems.sounds
almost as if the choke was stuck on.its not.after running the motor and cutting it off i have a hard time starting it up. i have a big puff of white smoke when it does start and another few minutes to run the carbs to where it would run at idle Ive put new plugs, plug wires.Ive checked my floats in the carbs.changed one ,the tab was broke on it.still didn't run right. if i could get some input it would be greatly appreciated
thank you

Re: Help With My1992 115 Merc. HEATING AND SMOKING

I've got a 1991 2+2 and besides checking the linkage on the oil pump, you need to check the plastic oil lines because they get really brittle and crack.
If you haven't tried running it with extra oil in the gas, that's the first thing I would try.
Bill

Re: Help With My1992 115 Merc. HEATING AND SMOKING

thanks for the input Bill i just converted it over to premix.that didn't help.but now i think Ive eliminated any oil issues.would a bad switch box cause a rattle in the motor
and cause it to run hot? Steve