Mercury 700s, need help. Water in fuel
12-11-2025 | 05:59 PM
#41
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On one occasion, without realizing it, the mechanical fuel pump came into contact with saltwater because a seal in the saltwater pump broke. The oil that lubricates the mechanical fuel pump was lost, and somehow the fuel pump internally came into contact with the water from the saltwater pump. What I do remember is that I only realized this once the mechanical fuel pump stopped working because it seized up and broke. That's when I learned to check the oil in the mechanical fuel pump regularly
12-11-2025 | 06:44 PM
#42
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From: Chicago
Looks like she`s running good!
18* rake props definitely help hop fyi.
mine was 70-90 also .. for some reason with the last set of 36x16x18 it moved down to 60-80.
I can power thru it pretty quick while using some tab and trim to calm it down.
After 80 MPH it`s ike a whole new world lol.
This is 80mph
18* rake props definitely help hop fyi.
mine was 70-90 also .. for some reason with the last set of 36x16x18 it moved down to 60-80.
I can power thru it pretty quick while using some tab and trim to calm it down.
After 80 MPH it`s ike a whole new world lol.
This is 80mph
12-11-2025 | 07:08 PM
#43
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Joined: Sep 2014
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From: Portland, OR
Diamond Dave yes sir I think I got it from the guy right after him there in Havasu. He said the motors had been gone through and refreshed but no paperwork. I still rolled the dice. It’s funny you mention the windshields, I thought they were actual glass so I had a guy come out to tint them just to find out they weren’t lol they look damn good though!
so if you look at the fuel setup in the picture, being there’s not a return back to the tank, for the bigger gets filter to be getting water in it straight form the tanks it would have to be coming from there. I think my next step will be adding a loop in the vent hose, and then draining a couple time like you said. Even thought about adding another filter in line to help clean it out faster and give me some more run time If that makes sense? If I was just getting it in the secondary filter after the cooler I’d think more about that being the issue.
When I had everything drained and gone through in August, one of the things we did do was injectors thankfully.
so if you look at the fuel setup in the picture, being there’s not a return back to the tank, for the bigger gets filter to be getting water in it straight form the tanks it would have to be coming from there. I think my next step will be adding a loop in the vent hose, and then draining a couple time like you said. Even thought about adding another filter in line to help clean it out faster and give me some more run time If that makes sense? If I was just getting it in the secondary filter after the cooler I’d think more about that being the issue.
When I had everything drained and gone through in August, one of the things we did do was injectors thankfully.
Last edited by Diamond Dave; 12-11-2025 at 07:26 PM.
12-11-2025 | 07:50 PM
#44
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Diamond Dave correct, top hose is going to the fresh water flush valve. I will have to check and see if mine is up that way. I do believe we are on the right track though.
12-11-2025 | 07:52 PM
#45
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ICDEDPPL That’s awesome man! I’m running 16.5X36-16 herrings right now, a buddy got it in my head to try some 38s so that might be the next move. I love the way it handles now just feel like I’m lacking some top end but maybe I’m wrong.
12-13-2025 | 02:06 AM
#47
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Joined: Jan 2021
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From: Gothenburg, Sweden
Mark didn't say anything about defective coolers with the 700s, just time catching up with them. The 700s that were in my 36 were built in October and December of 2010, and the failure happened in July of 2022. Getting more than a decade of use (including saltwater) out of them is commendable in my books. Both Bob and Josh have treated me great, and I can't say enough good things about all the work they've done for me since I picked up my 36 in 2020.
You are lucky to have Bob Teague’s house within walking distance of your home.
