mariner 150 overheat alarm

[rocks]

Just installed new water pump and pop-off valve,but overheat alarm still going off at 2200rpm's.I have good water pressure and flow from tell tale.The water from tell tale is approx. 160" Should the tell tale water be that hot??

 

[KCLOST]

Re: mariner 150 overheat alarm

What year motor?<br /><br />160F, sounds a bit high but not too much...<br /><br />150-155F is about where my water temps are at WOT.

 

[rocks]

Re: mariner 150 overheat alarm

1983 150 mariner. I don't have a temputure guage but did a manual off of the telltale water.This is my first outboard,I just didn't know if the telltale water was supposed to be at engine operating temperture.Thanks

 

[KCLOST]

Re: mariner 150 overheat alarm

No!!!!<br /><br />The overheat alarm on your engine is measuring metal temps of the head... It does not touch water... It goes through the cylinder cover water jacket and touches the head... It is set to go off at 240F...<br />I just posted a topic about temperatures for a V6 Black Max about a week ago....<br /><br />In regards to Metal head temps, you should see anywhere from 150F-180F at idle to 3000rmps, at WOT you may see up to 215F...<br />Water temps should be around 150-155F at WOT...<br /><br />Did you measure the water temperature while the overheat alarm was going off? Because if not, the head and water temps will drop very quickly once you power down....

 

[rocks]

Re: mariner 150 overheat alarm

Thanks KCLOST, I did check temp. while running and alarm going off.Does you telltale water come out hot?.I know mine is piped right off the thermostats which I also just replaced.Thanks again.

 

[rocks]

Re: mariner 150 overheat alarm

Also, the only thing I havent replaced yet is the sender.But, it doesnt look like much could go wrong with it? I also have a twin diesel boat,It isnt half as confusing as thi little outboard.

 

[KCLOST]

Re: mariner 150 overheat alarm

I know this....<br /><br />Just right after a full throttle run and if I reach back while the enine is at idle, I can only hold my hand under the tell-tail stream for about 4-5 seconds "max"...

 

[ronmold]

Re: mariner 150 overheat alarm

Disconnect oil warning module wire to make sure it's not causing the beep.