Thermostat Replacement on a 2005 Yamaha F90 Outboard (F90TLRD)

Easy thermostat replacement on the 2005 Yamaha F90 Outboard as part of the 300-hour service.
Thermostat: www.boats.net/...

[@CJRichardsadventures]

Thanks for the video. I have a 2006. I recently found out that mine is "making oil". From my understanding, the main causes of this is that the thermostat gets stuck open which causes the motor to run too cold and somehow that causes gas to get in your oil. Anyways, im giving it a shot. What all is included in a 300hr service?

[@GumpasShop]

To my knowledge the engine has a set operating temperature and will run rich ( excess fuel injected in the cylinders) to speed up the time it takes to get to operating temp. If the thermostat is stuck open it isn’t able to get up to temp to lean out the fuel burn. So some of that excess fuel could be getting past the rings and into the crankcase oil. The 300 hr service is engine oil, spark plugs, fuel filter, thermostat, lower unit oil and water pump rebuild. I will have more vids coming out on the rest of the service. My editor is a little behind……