On Sunday I ran aground and got myself pretty well stuck. Other than waiting for a few hours for the tide to lift me off, my only choice was to trim up the engine and “gun it”. It took a few minutes and a big mud geyser but I was able to get myself back to the channel, but not before setting off an alarm that I believe must have been a high temperature warning for my Yamaha 150hp 4-Stroke. After getting back in deep water I shut off the engine and it started back up, the alarm remained off and the engine has been operating fine since the incident. I must admit, I have done this a handful of times during the 300 hours I have put on my engine.
How much damage does this do to the engine and should I draw the mechanic’s attention to it when I get the 300 hour service completed in a few weeks? Thanks for any color.
I’d be most concerned about the water cooling passages. Sucking mud and sand in there can clog things up. When the water can’t flow around the head as it should the engine could overheat. Mud water and sand concoction being less fluid than water probably caused the engine temp to rise temporarily. As long as it all got flushed out it should be ok depending on how much and how long it overheated.
It ain’t no mystery…this beer’s history!
Hopefully you have had your water pump replaced by now if not I would replace it as the grit from the sand will eat up the pump.
I would be most concerned about the impeller, but if it’s running and peeing, I wouldn’t worry too much about it myself. If the impeller goes, it should be obvious because it will stop peeing hard, like we do when we get older. 
Just have it changed when it’s scheduled. That’s a personal, non-mechanic opinion, though, obviously. Ask a Yamahah mechanic what he thinks.
Gotcha Covered,
Lee Strickland
Strickland Marine Insurance Agency, Inc.
https://stricklandmarine.net
843-795-1000 / 800-446-1862
i fish shallow alot
therefore i stir mud almost everytime im out
just flush properly and change water pump on schedule and you should be fine
www.teamcharlestonmarine.com
www.joinrfa.org
Thanks for adding the professional word on it, Chris. It’s not uncommon when I fish, either. Never had a pump/impeller fail (on an outboard) yet.
Gotcha Covered,
Lee Strickland
Strickland Marine Insurance Agency, Inc.
https://stricklandmarine.net
843-795-1000 / 800-446-1862
I’ve never had an impeller fail either. Then again I’ve never kept a boat long enough for that to happen so what do I know.
Boatless
I had the exact thing happen. Alarm went off while kicking up mud. I shut motor off and lifted it up all the way. Noticed water intakes near propeller completely coated over with mud causing motor to get hot and alarm to go off. I had a pole with a brush on it. Reached out and brushed mud off and alarm went off right away after putting it back in water. I just made sure I ran it allot after in clean water and flushed good when got home. No problems.
19’ Seapro 150 Yamaha