Sierra 18-3549 Thermostat for MerCruiser 1458686
- Brand:
- Sierra
- Part no:
- 18-3549
Where to buy
View on Amazonpaid link
This is the Sierra thermostat 18-3549, listed against MerCruiser number 1458686. It is described as 120 deg. The fitment list opens with Mariner 6, 8 and 9.9 two-cylinder models from serial A197112 onward and runs on to other Mariner outboards. Check your engine and serial number against it before choosing.
Our take
The 120 deg figure is the first thing to compare with the thermostat you are replacing. The fit list starts with Mariner 6, 8 and 9.9 two-cylinder engines from serial A197112 onward, so confirm both before fitting it.