Review on 🌡️ Sierra Thermostat SR18.3554 - White: Innovative Efficiency for Optimal Temperature Control by Gopal Baltimore

It fits perfectly, but you need to buy two additional items to go with it. They are listed below. They come in multiple packs, but you only need one of each. I couldn't find much information online to replace this, so I took a bit of a risk to get everything. I will add some photos to give others a little more guidance on how to do this. The manifold will come loose after you loosen the two screws, but it will likely be glued pretty tight. Once the manifold is off, you should remove the old thermostat, which is held in place with the existing o-ring. Again this will probably be badly rusted but I used two flat head screwdrivers and eventually figured it out. The old thermostat should pop out fairly easily once the o-ring is removed. In one of the photos you can see side by side that the old thermostat is corroded in the open position. I scraped the old gasket off both the manifold and engine block with a razor blade and then used a pipe cleaner to clean the thermostat and new o-ring. There is a small lip where the thermostat fits perfectly. There doesn't seem to be a specific orientation to me that the thermostat should be in the manifold. The O-ring snapped into place surprisingly easily. I think I used a screwdriver to gently push it in. You don't want to damage it. The thermostat gasket simply sits between the manifold and the engine block. align holes. (I temporarily inserted a long screw to hold one side while I leveled the other side) Tighten and reconnect the hoses. super easy. Much luck! Sierra International 18-7170-9 Marine O-Ring - Pack of 5 Sierra 18-0398-9 Thermostat Gasket - Pack of 2