Quicksilver 8M0109441 Replacement Thermostat for MerCruiser Engines

Generally, it's a good idea to replace these thermostats every few seasons, depending on how often you're on the water. I never had issues with the thermostat in my Mercruiser 3.0 Alpha One (2008 Bayliner), but the thermostat was definitely the original, had never been replaced. Before installing, boil water and drop the new thermostat in to make sure it's opening properly. Biggest problem with thermostats is they get stuck open, which won't overheat your engine, but won't allow it to run optimally. If they get stuck closed, the engine will overheat. Quicksilver parts tend to be well made and more reliable than the no-name brands out there, but their parts are somewhat more costly. Either way, for $30, and about 10-15 minutes to install, it's worth replacing.The biggest hassle with the installation is the plastic sleeve within the thermostat housing. It's tough to remove. Easiest way to get it out is to flat out break it with a flathead screwdriver. I recommend buying a replacement plastic sleeve and the proper gaskets prior to installing. There's a small ringed gasket that goes underneath the thermostat as well. The plastic sleeve will not likely sit flush to the housing even after tapping it in with a rubber mallet or wooden block, though once the bolts are ratcheted in it should end up flush with the top of the housing. After installing, throw the muffs on your lower unit and run the engine to ensure it doesn't overheat. If the thermostat is working properly, your engine temp should hover around 175F, give or take a few degrees. The Quicksilver thermostat worked as it should, and should hold up for several boating seasons.

le premier n'a pas fonctionné la température été très élevé....j'ai commandé un deuxième et celui ci est parfait la température ce maintien entre 170 et 185 degrés.

Exact OEM replacement for my mercruiser 3.0. Changed out what looks to be the original thermostat installed at the factory on my 2008 Tahoe Q4 boat. Old thermostat had 07 & 160F on back of it. My thermostat was rusted the hardest part was getting the plastic retainer clip out but still was a 10 minute job from start to finish very easy install.

A good factory item.

Perfect factory replacement. Replaced 15 year old salt water rusted TStat.