Running at the optimum temperature maximizes performance. A malfunctioning thermostat can cause an engine to run outside of its ideal temperature reducing power and efficiency. The fix can be as simple as replacing the thermostat. This Sierra complete thermostat kit is pre-assembled to save you the time of researching and gathering individual parts. Each component in the kit is engineered to meet or exceed Johnson/Evinrude specifications. Included are: thermostat, thermostat gaskets, thermostat grommet (V6 Crossflow), rubber valve V6 Crossflow), valve spring (V6 Crossflow), poppet relief valve, valve cum (V6 Crossflow), retainer (V6 Crossflow) and fasterners. Sierra pre-assembled kits allow you to focus on replacing the thermostat and not on sourcing parts. Key Features Kit components meet or exceed manufacturer specifications Pre-assemble kit saves time searching for parts Compatible 150hp and up Johnson/Evinrude outboard engines manufactured before 1993; with your outboards serial number use our Engine Part Selector or call 1-800-BOATING to confirm this thermostat kit is correct for your outboard Replaces GLM p/n 13280 The Sierra Engine Parts Selector In addition to thermostat kits, we offer a wide variety of other engine parts manufactured by Sierra. To see if we have the part you need, see ourEngine Parts Selector, where you can search by engine make, serial number and model or year of manufacture