i have a 1988 mariner with scalding hot water coming out the pee hole any suggestions

[GlenHofstrom]

if anyone has any insight on a 1988 mariner 150 hp mag II, i have scalding hot water coming out the pee hole does anyone have any insight on this issue any help would be greatly appreciated

[bhile]

When is the last time the impeller and thermostat was changed?

[aussieflash]

In the water?On the hose?strong stream or weak stream?Your stats only begin to open at
around 60c or 140f.My engine at idle on hose gets steamy hot after 10 minutes,I wouldn't say scolding though.What's your temp gauge say,is the overheat alarm sounding?

[GlenHofstrom]

I had it on the water to test it out, just bought the boat engine has been serviced yearly, as far as the maintenance records, the water is very hot to touch meaning if u run your hand under it you have to jerk it away, there is no temp guage working on it now and there has been a overheat safety horn installed on the motor that does has not gone off, the stream of water is strong im not sure when the impellar and thermostat have been changed, was planning on opening it up today to take a look at it, just want to have some knowledge of what to look for when i do, is there a possibility that something can be clogged??

[j_martin]

If the boat has a water pressure gauge, the first thing to do is go for a ride, and note what the water pressure is through the full RPM range. That'll be the best clue to what to look for.

You could have something plugged up, or you could simply have a bad water pump. Same hot water out of the tell-tale, but totally different approaches to repair.

hope it helps
John

[waynelk]

As previously mentioned the stat opens at 140 deg. so it will be hot water coming out of these motors. I can not hold my hand in 140 deg. water for very long. Without a Temp. gauge or a water pressure guage it's a guessing game? You could put a thermometer in the pee stream for reference but it's crude at best.

[GlenHofstrom]

tomorrow going to put a thermostat on it and see what temp it is running at but does anyone have any insight on what type of grease or lube that that lower unit may need, still working on getting a manual for this exact motor so if anyone has any info that would be great

[luckynickles]

i use the best lower unit oil out there its a lot cheeper than replacing those gears there about 500 dollars to replace some of the old timers say to use grease but man i did that to a twenty five and i had to replace them so take it at your own descression on the oil

[j_martin]

tomorrow going to put a thermostat on it and see what temp it is running at but does anyone have any insight on what type of grease or lube that that lower unit may need, still working on getting a manual for this exact motor so if anyone has any info that would be great

Spec is Mercury high performance. If it has other in it, put HP in it and change it out after a few hours. It doesn't get along well with standard lube.

If the engine has the original LU on it, it's a 4" 1.78:1 unit. It'll stand up, but it has to be maintained right. I even surface drive mine a bit with no issues. Wrong lube, wrong clearances, bad seals, etc and you'll put the pinion out the side in a heartbeat.

If it has a 4 1/2 inch, 1.87 LU on it, the above scenario has already been done.

[aussieflash]

Your in luck,my manual is the same for your motor,Mariner 150 magnum II.
Service Manual #90-97658--3 (by Mercury)....not Seloc or any of the other shabby ones.