T- Stat wont budge on Mercruiser 305

[Backyardhockey]

It's a 1985 MR 200 Serial # A 389809. I can not get the thing out. I do not see an o ring of any type. Son, good eyes, says the word "motor" is stamped on it. I've tried pulling, prying, and cutting. Feeling stupid as I expected this to be very quick. Searched the site figuring others would have had an issue but not finding anything. Anyone educate me please?

 

[JustJason]

Re: T- Stat wont budge on Mercruiser 305

you can try heating the housing a bit. after that its pry, ply, whack, twist, cut, yank, etc etc

 

[kamby]

Re: T- Stat wont budge on Mercruiser 305

I dont think your supposed to see the word engine on the thermostat, it maybe installed backwards, but im not sure. Just gotta pry it out dont plan on saving it. Try some pb blaster or penetrating oil and try twisting it.

 

[Backyardhockey]

Re: T- Stat wont budge on Mercruiser 305

Yes, when my son said the word "motor" I was concerned. But the T-stat has been in there the 5 years I've owned the boat, If not all 24 years. Temp has always, before this year, been running at 180. This year it's at 135-150 We do NOT see the spring side, we are seeing the side with the "arch" when we take the housing off. I'll try to post a picture. Time for some C4?

 

[mkast]

Re: T- Stat wont budge on Mercruiser 305

I might suggest using a tap on the intake manifold bolt holes before reassembly, they can become quite corroded.

 

[Arrow21pilot]

Re: T- Stat wont budge on Mercruiser 305

When I took the housing off my 350, the thermostat was welded in to the housing. When we tried to pry it out, the housing broke and that was about a hundred and a half to replace. If you take the full housing off, you might be able to tap it out from the bottom.