1985 Mercruiser 260 - Conflicting Info - Thermostat Install

[DeepImpactFishingTeam]

Hi All, I removed the thermostat from my 1985 Mercruiser 260 (350 GM) and went to reassemble with new gaskets, sleeve, and thermostat of course, except the way it WAS assembled is different than the way my factory service Manual (Service Manual #9 for GM V8 Engines) which dictates the order of re-assembly. Further confusion is provided courtesy of MercruiserParts.com, which shows the order of assembly to be different than either of those two previously mentioned ways of assembly.

In short,
1) The way the thermostat was installed was as follows: Cork-O-Ring gasket, thermostat, sleeve (with lip on bottom), cover gasket.
2) Service Manual states sleeve first with lip up, then cork O-gasket, then thermostat, then a cover gasket, then a steel separator (wasn't in my motor?), followed by another cover gasket. (I would assume the new gasket I got, which has a blockoff built into the gasket is the reason i don't have a restrictor plate...?)
3) Mercruiserparts.com's diagram has thermostat, cork o ring gasket, sleeve (with lip down?), cover gasket.

Anyone happen to know which is right?? Any help is appreciated!

Mercruiserparts.com Link to diagram for reference: http://www.mercruiserparts.com/Show...r=1077&bnbr=160&bdesc=STANDARD+COOLING+SYSTEM

Thanks,
Robert

 

[Chad Flaugher]

Not a Mercruiser guy here, but logic would suggest that if it ran great for years the way it was, and finally failed just like every thermostat does when they get old, you should install the new one exactly like the old one was installed. If the boat is new to you and had problematic issues with temperature control, only then would I consider changing the configuration.

 

[DeepImpactFishingTeam]

The motor was a bit erratic in temperature, hence the thermostat change -

 

[Chad Flaugher]

Always, or just recently? Have you changed your impeller?

 

[DeepImpactFishingTeam]

I know the impellar was weak, that is now changed. I just need to know the proper way this thing is suppose to be reassembled....

 

[Chad Flaugher]

I wish somebody else would chime in. In my opinion, the way it was is the way it should be.

 

[keith2k455]

I honestly feel it's a loaded question. Maybe flip a coin - heads match the manual, tails match the way it was.

I'd put it the way it was and watch temp. Take rtv sealant on first trip out in case you need to change it on the water.

 

[keith2k455]

Ok... I looked at the diagram. Main thing is item 8 and thermostat orientation. I think the rest won't make much difference, as long as its there and fits without force.

 

[DeepImpactFishingTeam]

Anyone else have any input???

 

[Faztbullet]

Should be like this.......

 

[DeepImpactFishingTeam]

that is not my thermostat housing unfortunately. I Just followed the merc part dot com draw as that was very close to how it was assembled, with the only different being the cork gasket was on the other side of the thermostat. Will monitor temps during spring on land testing to ensure all works prior to launch.

Thanks!

Robert