Johnson 115 overheating on initial startup

[bksah2]

Heres something that a little odd ,,I picked up a 115 Johnson 1993 I have replaced the thermostates and clean all the water passage ways under the head covers put the head covers back on,, left off the the 2 small hoses that go to the thermastate houseing to see what kind of water flow i was getting ,,Start the motor and i got great water flow reconnect the hoeses to the houseing run some earns,,,,,, about 7 hours later i start the motor and the hot buzzer goes off ,,turn it off let sit for 5 mins and then restart the alarm goes off
Only on cold startup does the alarm come on

[cterrebonne]

Originally Posted by bksah2

Heres something that a little odd ,,I picked up a 115 Johnson 1993 I have replaced the thermostates and clean all the water passage ways under the head covers put the head covers back on,, left off the the 2 small hoses that go to the thermastate houseing to see what kind of water flow i was getting ,,Start the motor and i got great water flow reconnect the hoeses to the houseing run some earns,,,,,, about 7 hours later i start the motor and the hot buzzer goes off ,,turn it off let sit for 5 mins and then restart the alarm goes off
Only on cold startup does the alarm come on

does it come on as soon as you turn the key on? Or does it come on when the engine is idling?

[bksah2]

it comes on when running ,,got great pee hole flow ,,does not mater weather its idling or fast ilding

[THEFERMANATOR]

Does it have oil injection? I would suspect a bad overheat sensor, or blown bocking diode though from your description. Also the early style self test warning horns do fail and go off sometimes.

[bksah2]

The oil injection has beed disconnected gas oil mix.
The temp. sensors are right on the money, when they hit 200 degrees (reading with my temp. gun the alarm goes off)
the problem is that the heat transfer from the water on the inatial startup to the stats takes too long,, all most like its pumping to good.
" blown bocking diode" What is that??

[THEFERMANATOR]

If the alarm is going off when teh sensors aren't triggering it, then soemthing else is shorting it out or the alarm itself is bad. 95- used a 3 wire alarm horn with it's own self test to make the horn chirp for a second upon start-up. Sometimes they fail and go off all the time though. The blocking diode is there to keep the FAST start system in the power pack from triggerrign the warning horn.