87 evinrude 50....problem not solved

[tylerr83]

ok guys...thought i had everything worked out with my 87 evinrude 50 (new water pump assembly, new thermostat)...went to take the boat for a little spin today and it overheated again at the dock...when run at my house with the muffs on, no issue.....i noticed today that the pee stream is much weaker when the boat is in the water than when its hooked up to the muffs....i figure this is because the water is being forced in....but i also noticed that there is a signifacant amount of leakage from the seam between the lower unit and the midsection....is this normal or is it possible that i have an issue there....maybe something not lined up properly from when i reinstalled the lower unit?

this is my best guess because it seems like even thought this leaks, the pressure from the hose feeds enough water to the impeller to keep things cool, but when its in the water theres not enough pressure going up the midsection because of the leak? just a guess....other than that idea i'm kinda lost here

 

[HighTrim]

Re: 87 evinrude 50....problem not solved

You are correct in your thoughts. When an outboard is on the muffs, it is being 'force fed' the necessary cooling water, by passing the water pump. When under load, it is no longer force fed. I would look to your water pump. What was the condition of the actual housing during reno? Did you change the housing along with the impeller, or the impeller alone?

The water leakage at the seam is normal and nothing to worry about. The cooling water is spent by that time.

 

[tylerr83]

Re: 87 evinrude 50....problem not solved

the entire water pump assembly is new...housing, impeller, gaskets...my only other thought is that maybe its not overheating and my temp sensor is bad? i can touch the block and heads for a few seconds, its hot but doesn't burn immdiately...if normal operating temp is in the 140-160 range then that makes sense....it does seem however to run cooler with the muffs hooked up

 

[tylerr83]

Re: 87 evinrude 50....problem not solved

before i get carried away worring about temp sensors and such i guess my best recourse is to drop the lower unit again, check the new water pump and make sure i didn't do something stupid like install the impeller going the wrong way...dont think i did but who knows....i suppose the there could also be a crack in that waterline that runs from the pump through the midsection to the powerhead....or another stupid mistake like misaligningthe pump and that water line...for my wallet's sake i hope this is the case

 

[tashasdaddy]

Re: 87 evinrude 50....problem not solved

yep!!

 

[tylerr83]

Re: 87 evinrude 50....problem not solved

ok, the lower unit is out...noticed a small pinhole almost like a weep hole, in the water line (the line is copper)...but it doesn't look like its from corrosion (its perfectly round and clean) and almost looks like its suppsoed to be there....is this normal?

 

[tylerr83]

Re: 87 evinrude 50....problem not solved

i checked the water pump, and everything looked ok, the impeller was going the right way and everything, carefully put the lower unit back on and ran the motor in the water again....after 5 or so minutes of idle the overheat alarm is still sounding....i'm really lost....i talked to a tech today and he said like i've read on here that if you can touch the head or the block for 3-5 seconds its not too hot....which i can so i'm wondering if my temp sensor is the problem...how do i know if its functioning properly...is there something to look for here....or should is this an unlikely cause of the problem...the motor idles and throttles up fine....so i dont know what else could be causing the problem....i'm so frustrated now that i'm considering taking it to a local place that services johnson/evinrude but they told me today that if i brought it in on monday i wouldn't have it back till may at least ...so if theres anything else i can do i'd rather do this...really want to get out and do some fishing...

 

[tylerr83]

Re: 87 evinrude 50....problem not solved

a few other things i should mention...i've read that the thermostat is supposed to open at about 140....meaning the motor should idle just a little warmer than this and the temp sensor would be set somewhere near 200....if i were really running at 200 degrees then i'd guess i could not touch the head at all without it burning immediately....aside from a bad sensor, it seems like maybe i could have an issue with the deflectors? other than this if you guys have any suggestions i'd really appreciate them...
thanks,

Tyler