Mikeg1585

Hi everyone, I have twin 2016 mercury 150 fourstokes One of thethere is water coming out of the exhaust port and bubbling and bogging a bit at idle. Any idea what could cause this? My buddy said it could be a bad thermostat. It runs a tad cooler than my other motor. Here's a video of them both running. Thanks for any info. . https://youtu.be/dvEHxZibOWI

Arda

Hi Mike, I have a 2014 150hp mercury and having the exact same issue. Did you find out what was causing this? And how did you fix it? Thank you, Arda

sundancekid

Stuck thermostat usually causes that.

Arda

Thank you. How do I fix the stuck thermostat? Do I need to replace it?

sundancekid

Yes, replace it. It’s on top of the block in the back, one oetiker clamp and two 8 mm bolts hold it on. You will have to remove the flywheel cover for access, I believe it’s a 10 mm. It comes as a complete assembly, takes 15 minutes to change.