83 evinrude 140 heat issue

[centuryexpress]

Ok, I did a bunch of searching, but I am still having an issue, I think. Last year when i got outmy boat, on the muffs, the overheat buzzer came on. Not wanting to deal with it, I just refogged the motor and put her back.
So I get her out this year, put on the muffs, and start her up,, The temp gauge with muffs gets up to about 180-90, and the starbord top head gets hot,, you can keep hand on for a while, but not indefinately, buzzer did not go off. Port head stays very cool.
I went ahead and changed the thermostats, ,no change. The impeller is fine, good pressure. When I take off the hose coming from that head to stat housing, I have good water flow, and head cools right off. Soo, impeller ok, new stats, and head still getting what seems to be too hot. Is this a function of running off the muffs (does not make sense, with a pressurized supply of cold water going in)... If the deflectors in head were not in place, then it would not cool off with hose off either, correct?? Wondering if I should just pull the stat on that side, would it run ok or be too cold?,,,
'Any help appreciated.
Oh, the vent hole in the housing is clear, just for info. freshwater boat.

 

[kenmyfam]

Re: 83 evinrude 140 heat issue

Stats should be in place. Do you have the vernatherm stats ?? if so I had a rubber donut that it fits against get twisted. Have you flushed the system, tested the stats are opening at the correct time and replaced the impeller and water pump housings ???

 

[kenmyfam]

Re: 83 evinrude 140 heat issue

And welcome to iboats.

 

[centuryexpress]

Re: 83 evinrude 140 heat issue

Thank you for the reply and welcome. The stat kit is sierra, if I recall without looking. I did not pan test new stats. I did test the old ones, as well as reversing their positions with no effect. I did not service the pump, as I said the pressure and flow seem fine. thanks again.

 

[kenmyfam]

Re: 83 evinrude 140 heat issue

Can you test the head temps with an infra red tester to actually see what temp they are ??? Another way is with temp sticks.

 

[centuryexpress]

Re: 83 evinrude 140 heat issue

bmp

 

[centuryexpress]

Re: 83 evinrude 140 heat issue

Good call on the IR thermo,, it appears it is not over heating, gets up to about 150, then drops back down I assume as thermostat opens. Oddly the port bank runs way cooler then starboard bank. So my gauge is way off, I dont recall if my buzzer used to come on when I would first start boat or not,any ideas on how to troubleshoot buzzer/gauge circuit? thanks.

 

[kenmyfam]

Re: 83 evinrude 140 heat issue

Good call on the IR thermo,, it appears it is not over heating, gets up to about 150, then drops back down I assume as thermostat opens. Oddly the port bank runs way cooler then starboard bank. So my gauge is way off, I dont recall if my buzzer used to come on when I would first start boat or not,any ideas on how to troubleshoot buzzer/gauge circuit? thanks.

Were you testing the temp on the muffs ??? I notice that mine is even when on the lake but differs a bit each side on the muffs.

 

[centuryexpress]

Re: 83 evinrude 140 heat issue

Yes, tested on muffs. way cooler on port bank. Tried shorting the temp coupler to test alarm, found that the buzzer is also broken. I guess I can just wire in a radio shack buzzer. So will try to find a replacement and see if I can figure out what the hell is going on here.

 

[kenmyfam]

Re: 83 evinrude 140 heat issue

Check it out on the lake with the infra red after a warm up and short burst of speed.

 

[emdsapmgr]

Re: 83 evinrude 140 heat issue

If you are going to replace the head temp switch, you will have to take off the head cover. While you have the cover off, check the coolant passages in the head for debris, like sand or weeds. The engine has two cooling phases, one when at idle (and all water flow goes through the stats,) the other when on plane, (when the pressure relief valves open for extra coolant flow.) You need to know if it overheats in both phases, or only when idling. You should see temps in the 140-150 at idle. Maybe lower when on plane, depending on how cold the water is... While 180/190 won't set off the overheat alarm, it is too hot. Make sure the two pinholes in the thermostat housing valve body are both open. If one plugs up, it can cause an overheat on that side of the block. The head temp switches will trigger an overheat horn at 212 degrees and shuts it off when temps get back down to 175.