1999 Mercury 200 EFI motor locked up

" My husband has a 1999 Mercur

" My husband has a 1999 Mercury 200 EFI that he has had since 2000. It had never given him any trouble until 2002. It would run fine, then all of the sudden the motor would shut down. The first time it happened the alarm had just gone off when the motor shut down. It actually locked up. Fortunately it was under warranty so he took it in and had it fixed. The dealer told him that it had over heated and they rebuilt it. Since then this very same probem has happened as of yesterday 4 times. The second time he took it back to the dealer, they said that it had overheated again, they rebuilt it and put a seperate gauge on it to watch for the temp. to spike. It didn't show any overheating when it happened the third time. So they rebuilt it again and put "cups" on the sides to help force water into the motor. This obviously didn't help. Does anyone have any clues as to what could be causing this problem? I have tried to find out if the manufacturer has had problems with this specific motor but no one seems to be able to help me. I don't want to hear that the motor needs to find a new home, my husband has already suggested that. I would really like to find the cause and the solution to this "unique" problem. "

My '86 Evinrude 110....Th

My '86 Evinrude 110....Thinking of replacing it with a 150 4 stroke Yamaha...which weighs 466 with short shaft...

What does the '86 Evinrude weigh???...stranded with no info
Thanks

" rpearson.
Apart from the us

" rpearson.
Apart from the usual checks for overheating like waterpump, waterflow, thermostats, and relief valve...as im sure these have been checked, has the oil injection system been checked...a failure in this area will turn up similar symptoms...is the motor "using" oil? Has the warning system been checked? Does the buzzer come on when it overheats? "