2006 Mercury 40hp 4 stroke temp alarm

Dbnail

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Joined
Mar 20, 2016
Messages
5
I was fishing today and ran over a sand bar at an idle. Killed engine and raised motor and notice sand in lower unit (corse sand). Removed and cleaned lower unit. When I crank back up had a good stream and didn't notice any issues. When I went to put the boat on pad alarm went off, was solid beep saying temp alarm and then engine shut down. Idled rest of the way in. I figure I sucked up some sand. The pee stream was fairly cold and not warm as usual. Slightly warmer than the river water.

I have had this happen before with another boat with a 200 proxs and the thermostat was stuck open causing the temp alarm to go off. Will this do the same thing with this smaller engine. Also, will backflushing the engine fix it if their is sand in there or will I need to do more? I plan on going ahead and replacing the impeller when I pull the lower unit to inspect for debrie.
 

Dbnail

Recruit
Joined
Mar 20, 2016
Messages
5
I did a backflush. Shouldn't water be coming out of all the pick up holes in the lower unit? I tried to upload a video but I can't for some reason.
 

Dbnail

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Joined
Mar 20, 2016
Messages
5
Could really use some help. I read in another post on a search that mentioned pulling the block. I really hate to go that far if I don't have to.
 
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