1993 Johnson 150hp temperature buzzer goes off at wide open throttle

[flbassin]

I have a 1993 Johnson 150hp. outboard & my temp. buzzer goes off after running wide open for a few minutes. water pressure is about 25# when this happens & I have water coming out the pee hole. I checked the thermostats & both of them were in pieces. I took them out & ran it wide open for several miles & the temp. buzzer didn't go off. I replaced both thermostates with johnson, Evinrude part #0435491 thermostates & ran it wide open & the buzzer went off with the new thermostates in it. Is it ok to run it with the thermostates out. It doesnt show any water pressure with them out, but the buzzer doesn't go off. Thanks for any info.

 

[OBJ]

Re: 1993 Johnson 150hp temperature buzzer goes off at wide open throttle

FL...it's possible you got a bad t-stat. You can get the overheat alarm from either head. Next time, pop the hood and see if either head is hotter than the other. You really don't want to run without the t-stats.<br /><br />Also, your tone could also be caused by a fuel flow restriction. There is a vacuum switch on the fuel rack that will sound the steady tone if there is a problem with the fuel flowing to the pump. Check out your fuel lines. Make sure none are kinked and would cause a fuel flow problem.<br /><br />And.....Welcome to iboats!

 

[seahorse5]

Re: 1993 Johnson 150hp temperature buzzer goes off at wide open throttle

Originally posted by flbassin:<br /> I have a 1993 Johnson 150hp. outboard & my temp. buzzer goes off after running wide open for a few minutes. water pressure is about 25# when this happens & I have water coming out the pee hole.

When the horn sounds, does the motor slow down to about 2500 rpm and run rough? If not, then OBJ is on the right track by saying it may be the fuel restriction warning. It it is a fuel restriction, then the horn should stop as soon as you pull the throttle back to idle.

 

[flbassin]

Re: 1993 Johnson 150hp temperature buzzer goes off at wide open throttle

Originally posted by seahorse:<br />

Originally posted by flbassin:<br /> I have a 1993 Johnson 150hp. outboard & my temp. buzzer goes off after running wide open for a few minutes. water pressure is about 25# when this happens & I have water coming out the pee hole.

When the horn sounds, does the motor slow down to about 2500 rpm and run rough? If not, then OBJ is on the right track by saying it may be the fuel restriction warning. It it is a fuel restriction, then the horn should stop as soon as you pull the throttle back to idle.

 

[flbassin]

Re: 1993 Johnson 150hp temperature buzzer goes off at wide open throttle

When the horn goes off the motor starts missing & will not run until I turn the engine off & back on. As long as I run it half throttle it run ok.

 

[OBJ]

Re: 1993 Johnson 150hp temperature buzzer goes off at wide open throttle

It does sound like the SLOW is taking over Prestion. Next time, check the heads as prviously outlined.