1993 4.3lx thermostat housing

[93maxum4.3lx]

4.3lx mercruiser.

I removed the thermostat as part of winterization, and it was really a pain to remove. I have a six hose design, with a flat plate cover for the thermostat itself. Anyways, the book diagram shows a spacer above the thermostat, and an O-ring below it; however I seem to have neither of these items. boat maintained temperature properly and I honestly don't believe the thermostat housing has ever been off (factory mercruiser paint on the bolts was untouched and the gasket was more or less part of the metal).

Do I need to worry about this spacer? Should I replace the housing? I can't find a picture of anything that matches mine online.

thanks!!!

EDIT: the housing I have APPEARS to be like 16413-A9. Also, the spacer I speak of, is described in other sources as a sleeve. If anyone can shed light on what I need to / should do, that would be great. THANKS!

EDIT 2: I believe this is the correct diagram for the system I'm working with:

https://www.marinepowerservice.com/BoatingStore/lookup_parts_mercyear2.cfm/coll_style/04/block_nbr/120/index_nbr/1599/doc_part_nbr/801874%2093/requesttimeout/3000/search_text/16413A9/pickdrive/16413A9/path/801874%2093/pickyear/0.cfm

 

[wewefirex2x]

Re: 1993 4.3lx thermostat housing

The piece you are referring to as a spacer is the sleeve for the thermostat. I have also found that not always do they come in a kit. You want might to look a little closer inside the thermostat housing, could be hiding behind some gunk. Turn the housing over, with even pressure around stat, try hitting the thermostat with a screwdriver to work loose. I have also seen the sleeves in plastic and metal.

 

[Bondo]

Re: 1993 4.3lx thermostat housing

Do I need to worry about this spacer?

Ayuh,...

Both it,+ the O-ring are Required...

 

[93maxum4.3lx]

Re: 1993 4.3lx thermostat housing

so, it's time i get this fixed.

I can get the O-ring and plastic sleeve for the housing I have, no problem.

however, some web sites seem to indicate that my housing has been replaced/superseded by a new housing.

I believe the housing I have is P/N 16413A9.

I believe the housing that has superseded it is 87290A23.

What is the point of the replacement? is it somehow better or fix a fundamental flaw in the housing i currently already have, and thus would be a good idea to switch; or don't worry about it and use what I have (just replacing the o-ring and sleeve?)

thanks!

 

[Chris1956]

Re: 1993 4.3lx thermostat housing

That design worked for many years. I would continue to use it until it rots our completely. Om my '88 Alpha, the sleeve was stainless and was s tight fit into the thermostat housing, but it pinched the thermostat and made it fit tight.

BTW - Why do you remove the thermostat to winterize that motor? The best way is to drain the water from the block and mannys, and dump full strength antifreeze into the six hoses. When you see the AF emerge from the drains, put the plugs back in and fill 'er up via the hoses. Dump some down the raw water hose to flush out the PS cooler and water pump impeller. Let some overflow the elbows and exit via the prop