Indmar Assault 325 Thermostat and Gasket

[SHungerford]

Looking for some advice on the correct gasket for a thermostat replacement on a 2012 Moomba Outback with an Indmar Assault 325.

Do these look like the correct parts:

Thermostat: https://global.bakesonline.com/indmar-160-degree-marine-thermostat.html

Gasket: https://global.bakesonline.com/gasket-indmar-thermostat-2-bolt-housing.html 

2 seasons ago the impeller came apart mid-season and the engine overheated. Both exhaust pipes were cracked but thankfully no other engine damage. Over the past few days the temp gauge on the dash has been acting a bit strange. At speed in the course it's fluctuating between 135 - 150, but at idle or while moving slowly the gauge rises to around 180. This is new behaviour for the gauge, in the past once the engine has warmed up the temp gauge generally sits at 150.

I checked the raw water strainer (clean), pulled the impeller (perfect condition) and checked the transmission cooler for any residue impeller debris from past impellers. 

I'm thinking it could be the thermostat acting up, but any other ideas?

Thx All

[UWSkier]

24 minutes ago, SHungerford said:

Looking for some advice on the correct gasket for a thermostat replacement on a 2012 Moomba Outback with an Indmar Assault 325.

Do these look like the correct parts:

Thermostat: https://global.bakesonline.com/indmar-160-degree-marine-thermostat.html

Gasket: https://global.bakesonline.com/gasket-indmar-thermostat-2-bolt-housing.html 

2 seasons ago the impeller came apart mid-season and the engine overheated. Both exhaust pipes were cracked but thankfully no other engine damage. Over the past few days the temp gauge on the dash has been acting a bit strange. At speed in the course it's fluctuating between 135 - 150, but at idle or while moving slowly the gauge rises to around 180. This is new behaviour for the gauge, in the past once the engine has warmed up the temp gauge generally sits at 150.

I checked the raw water strainer (clean), pulled the impeller (perfect condition) and checked the transmission cooler for any residue impeller debris from past impellers. 

I'm thinking it could be the thermostat acting up, but any other ideas?

Thx All

There are probably two gaskets there.  One at the lower union where the housing meets the manifold.  That's the gasket you posted in the link.  The second will be between the two pieces of the tstat housing.  At least, that's how it was on my Indmar Monsoon.  For that upper gasket, I bought some gasket material from Amazon and made my own.  It's an easy job with a crafting knife.

[SHungerford]

thx @UWSkier I went back and read the product descriptions more carefully, looks like I also need this gasket for the bottom: https://global.bakesonline.com/indmar-thermostat-gasket-3-bolt-housing.html