Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: How hot should it get
Posted by Bilito on 03/11/14 - 3:35 PM
#1
I have a 1997 Merc 40 hp 4 cylinder 2 stroke, oil injectd motor.
This motor does not have a thermostat housing, so no thermostat. The water coming out the pee tube has a lot of pressure but it is also very hot, you cannot hold your hand there for very long. How hot should it get?
Posted by ritzyrags on 03/11/14 - 8:58 PM
#2
Not as hot as the reported temperature.
Did you not carefully rev ed up your Outboard with proper flushing water pressure?
Posted by aeriksen on 03/11/14 - 9:18 PM
#3
A engine without a thermostat should not get that hot, warm but not hot, get a salt away product and flush you engine numerous times with it and hopefully it will dissolve any blockages
Posted by Tom W Clark on 03/11/14 - 9:24 PM
#4
The human hand can tolerate about 125 degrees of water temperature. A 40 HP Mercury is going to run a lot hotter than that. I wouldn't worry about it too much.
A much better test would be to scan the powerhead with an infrared thermometer looking for hot spots.
Posted by ritzyrags on 03/11/14 - 10:36 PM
#5
This question has been answered before.
Here is a link that has shared in their past experiences.
http://www.fishraider.com.au/Invision...opic=53998
I hope that a second opinion will have been of some help to you.
Posted by huckelberry145 on 03/12/14 - 8:16 AM
#6
Tom W Clark wrote:
A much better test would be to scan the powerhead with an infrared thermometer looking for hot spots.
Tom, would a theromelt "tempilstick" as we call it on the railroad work as well? Just thinking it would be cheaper.
Posted by Tom W Clark on 03/12/14 - 8:19 AM
#7
Yes, those melt sticks are commonly prescribed in outboard service manuals.
Infrared thermometers are not that expensive though. I've had a good one made by Fluke for years. Comes in very handy in the kitchen and backyard for cooking.
Posted by huckelberry145 on 03/12/14 - 9:34 AM
#8
Cool, I'll have to go check one out myself.
Posted by Bilito on 03/12/14 - 4:03 PM
#10
Made in China, how accurate can it be, plus or minus 20 degrees maybe
Posted by tmann45 on 03/12/14 - 7:50 PM
#11
Bilito wrote:
Made in China, how accurate can it be, plus or minus 20 degrees maybe
Whatever device you used to post this reply was probably made in China, how accurate is it?
But skip the $20 one and get the $36 one, it is a lot better and can be had for $25 or so on sale or coupon.
Posted by Tom W Clark on 03/12/14 - 7:59 PM
#12
My Fluke IR thermometer under-registers by about 1.5 degrees Fahrenheit in the room-temperature range. No idea how accurate it is in a red-hot coals barbecue.
But that is a very *
consistent* under-register which means it is very precise, though perhaps not accurate.
BTW, there are a couple used Flukes like mine on eBay now that you could buy for $25 or so. I paid about $100 many years ago.
Posted by Bilito on 03/14/14 - 3:57 AM
#13
WOW, What a coincidence, my next door neighbor came over last evening to show me his latest tool, it is an Infrared Thermometer from Harbor Freight. He went fishing today so I borrowed the thermometer and I am waiting for daylight and then I will run that motor and check the temps all over it and then report back here
I am gonna check it against a cooking thermometer my wife used to check the temps on meat
Stay Tuned..........
Posted by Bilito on 03/14/14 - 10:46 AM
#14
Just ran it
top cylinder spark plug was 110 degree F
Botton spark plug was 90 degrees
Pee hole temp was 110
Water did not get hot enough to even move the cooking thermometer which starts at 140
This was with my friends new Harbor freight laser infrared thermometer
Posted by Tom W Clark on 03/14/14 - 1:35 PM
#15
find a wall thermometer or the furnace thermostat in your home and shoot it with the IR thermometer and compare.
90-110 degrees sounds cold, though if the motor was only idling...
Posted by Bilito on 03/14/14 - 4:35 PM
#16
Tom W Clark wrote:
find a wall thermometer or the furnace thermostat in your home and shoot it with the IR thermometer and compare.
90-110 degrees sounds cold, though if the motor was only idling...
Fast idle