[aisnake]

First make sure that your model has a thermostat. Enter you serial number at www.mercurypartsexpress.com<br /><br />The water that sprays out the tell tale on a mercury is after it passes through the water jacket and through the tstats. So unless the tstat is fully open, which it might not be at idle, you won't get that strong of a stream. On a Johnson the water out the tell tale is just coming from the water tube, so it is always cool and strong.<br /><br />If your nervous though, drop the L/U and inspect the impeller. Check to see if it is damaged or if it has a spun hub. With the L/U off flush some water down the t-stat hole and see if anything falls out the water tube.<br /><br />Have you ever replaced the water pump and or tstat. You should. And like Rodbolt always says "it's better to replace the water pump and tstat, than water pump,tstat, and piston". Preventative maintainance is the name of the game. And these two are crucial.<br /><br />Good luck-<br />andy

[coinguy]

Re: 25hp Mercury Cooling - Thermostat Help

[wolfz0rz]

Re: 25hp Mercury Cooling - Thermostat Help

[videodude]

Included for free with this service

[AstroBloom18x]

The car's engine cooling system thermostat is a small valve within a cooling system passageway that opens and closes in response to the temperature of the circulating engine coolant. When your car is first started and the coolant is cold, the valve in the thermostat will be in the closed position, circulating the coolant flow only within the engine instead of flowing to the radiator, which allows the engine to warm up fast, promoting fuel efficiency, low emissions, and reduced engine deposits. Once the engine coolant reaches the design temperature, usually around 195 degrees, the valve will open and close as you drive in order to maintain a coolant temperature typically between 195 to 225 degrees Fahrenheit.

[rodin]

12-month / 12k-mile warranty

[melinamoore373]

Our mobile mechanics offer services 7 days a week. Upfront and transparent pricing.

[forsell1st]

Free 50 point safety inspection

[ech]

On average, the cost for a Mercury Mariner Car Thermostat Replacement is $170 with $75 for parts and $95 for labor. Prices may vary depending on your location. here

[cgrongs]

Hello everyone, first post but have been lurking for about 2 months. i just purchased my first boat, a 1972 Avanti 16 foot tri-hull. Im restoring it and making it a nice fishing boat for lakes and some ocean days. It has a 1981 mercury 50 hp 2 stroke outboard. I got the engine running but no stream of water out the tell-tale. I only ran it for about 10 seconds, it had water coming out of the prop. I ordered a new impeller kit so hopefully that fixes that problem. I also ordered a thermostat, but cant seem to find its location .. Im very mechanically inclined with cars/motorcycles, but this is my first outboard. does it have a thermostat? I ordered all the parts from right here on i-boats and the thermostat fit my serial number. any help/pictures will be appreciated. This site has already helped me a great deal with this boat, alot of knowledgable people here. Thanks in advance!

[kiba]

Re: 50 hp merc 2 stroke thermostat?

[alex_l]

EDIT: Another question. Will water come from the tell-tale immediately upon starting the engine? or will it take some time? sorry for the newb questions lol

[LaidBack]

Your Mercury Grand Marquis relies on a thermostat to control the temperature of the engine. When it goes bad, you’ll experience a number of different problems. Some of the most common symptoms of a bad thermostat are no heat, a spiked temp gauge, blown head gasket, and more.

[dete]

If your Grand Marquis runs too long without coolant circulating through the engine, the head gasket can blow. Signs of a bad head gasket include:

[loungedaddy]

As pressure builds around a bad thermostat that is stuck shut, you’ll notice that there may be coolant leaking around the thermostat housing. This leak is not the cause, but rather a symptom of your Grand Marquis’s bad thermostat. [links]