2003 Mercury 40hp 4 stroke overheats

[cassenbl]

i have a 2003 mercury 40hp efi 4 stroke serial number 0T783233. It has started over heating. I took to Mercury dealer and they had it for 4 weeks and $1000. Compression is good. Dealer put new water pump and thermostat with no effect. I just got done flushing motor with vinegar with slight improvement at idle but will still overheat after about 5 minutes of idle. I have the thermostat removed. Has very good telltale water stream. When running, the telltale stream goes from cold to luke warm back to cold. Right before it overheats the stream runs very hot and then turns cold again. Is there another thermostat besides the one I removed in the system that could be malfuctioning? Also when it overheats and I shut motor off I get a blast of water and air out of the telltale.
Please help,
Ben]

[cassenbl]

Anybody have an idea? Service manual does not really show much on cooling.

[cassenbl]

Again, very good water through telltale but engine block overheats. As I understand, telltale is a bypass and not a true indicator of water flow. Where does the telltale get it's water and where does the engine block get it's water? If I pull power head will I be able to see a possible area for problem? Please help.

[kichtang58]

Bán nh�* GTHL sổ hồng mới xây năm 2011, ngang 6,7m d�*i 25,5m. Nở h�*u 9,7m, đúc kiên cố phần nở h�*u 6,3x9,7 = 60m2. có điện 3 pha. Mặt tiền đường HT23, cách ngả 3 Đ�*i Liệt Sĩ 200m, hướng Đông Bắc, khu dân cư đông đúc, tiện kinh doanh hoặc cho thuê, nh�* trống giao ngay.

Xem nh�* tại địa chỉ 3D đường HT23

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