1990 Merc 350 cid thermostat housing?

[Boomyal]

I am asking this without having had the housing in hand. This is for a stock setup. Is there a trick to removing the thermostat from the housing once you have it off and in your hand. A friend tells me there is some kind of 'Sleeve' holding the thermostat in the housing and that you would break something trying to get it out.

Any experience or pictures, here? This is for a fresh water boat and he wants to put a 180° 'stat in it.

 

[NHGuy]

Remove the hoses, remove the bolts, take off the housing and take off the cover. Grab the old stat with some pliers and tug it out of there. Or stick a screwdriver in the stat and leverage it out. It's ok to break it, you aren't going to re use it. Now next thing and more important, raw water cooling gets 140 degree stat and closed cooling gets 160. Don't do the 180, it won't work right..
There is a sleeve, just give it a whack if it's stuck, it will come out. The sleeve is stainless steel and the housing is cast iron.

 

[Boomyal]

,,,,,, Don't do the 180, it won't work right.......

Why not? It is a carbureted motor so there is no conflict with fuel mapping like there would be with EFI, PLUS 180° is a much more efficient operating temperature compared to 160°.

I have been running a 180° 'stat in my 302/5.0 for years. My plugs last longer and my fuel economy is much better. Manufacturers use colder thermostats to keep salt from plating out inside the engines. They had no way of knowing where their boats would get used.

I will get a look at the housing and use your description to decipher it.

 

[alldodge]

I am asking this without having had the housing in hand. This is for a stock setup. Is there a trick to removing the thermostat from the housing once you have it off and in your hand. A friend tells me there is some kind of 'Sleeve' holding the thermostat in the housing and that you would break something trying to get it out.

Any experience or pictures, here? This is for a fresh water boat and he wants to put a 180° 'stat in it.

Howdy Boom, the sleeve most often comes out as NHGuy mentioned, but if it brakes, the cost is under 15 dollars most times. If I had your serial number might be able to figure out which one is installed.
Design 1 - 23-47508T
Design 2 or 3 - 23-806922

 

[NHGuy]

Boom, agreed on the carb motor doing better at higher temp. I only say use the OE design when I don't know how vigilant the operator will be on the temp gauge. 180 is a lot closer to 212 than 140 is. Only that.
And I defer to you experience. No closed loop etc there, just fuel and spark.

 

[Boomyal]

Howdy Boom, the sleeve most often comes out as NHGuy mentioned, but if it brakes, the cost is under 15 dollars most times. If I had your serial number might be able to figure out which one is installed.
Design 1 - 23-47508T
Design 2 or 3 - 23-806922

Are those outdrive seriel number, AllDodge, or motor seriel numbers? I may be able to get them today.

 

[Bondo]

Are those outdrive seriel number, AllDodge, or motor seriel numbers? I may be able to get them today.

Ayuh,.... Hi Boomer,.... I believe those are Merc part #s for the sleeve ya might need,...

They sometimes come out hard, spray it good with Fluid Film to soften the rust,....

 

[alldodge]

Are those outdrive seriel number, AllDodge, or motor seriel numbers? I may be able to get them today.

I would need engine serial numbers. On another side have a look below at the 2 links. They have different shapes and you could probably decide which one it is from with it looks like
Here is design 1 and look at item 7
http://www.mercruiserparts.com/Show...r=210&bdesc=STANDARD+COOLING+SYSTEM(DESIGN+I)

Here is design 2 and 3 and look at item 10
http://www.mercruiserparts.com/Show...=220&bdesc=STANDARD+COOLING+SYSTEM(DESIGN+II)

 

[Boomyal]

AllDodge, good illustrations. I did not get a chance to get over to the boat today. I will do it soon and post back. Are either of those thermostats a proprietary design or in spite of their surroundings are they a bit more universal?

 

[alldodge]

AllDodge, good illustrations. I did not get a chance to get over to the boat today. I will do it soon and post back. Are either of those thermostats a proprietary design or in spite of their surroundings are they a bit more universal?

Cannot answer that, nut my guess is they are universal. Have yet to find a proprietary design in auto industry. Only thermostat I found is proprietary is CAT and other heavy equipment