Fogging Mercruiser 5.0 MPI

alexvelarde

Seaman
Joined
Mar 4, 2011
Messages
54
How do I properly fog my engine? I used to have a carbureted engine, but now I have a fuel injected engine.

5.0L MPI (305 CID) Sterndrive EC
260 HP
Engine Serial Number: 2A047298
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
Messages
19,401
you get a small outboard tank 1/2 gallon of gas,, good squirt or two of fuel stabilizer, 1/2 pint of 2 stroke oil, mix well and connect to the fuel inlet at the fuel sep filter.
I`d worry more if you have the single point drain system
 

QBhoy

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Mar 10, 2016
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8,348
Wouldn't bother....causes more problems than it's worth. If you are worried, takes the plugs out and squirt some protective lubricant in each cylinder or a 2 stroke mix in a squirt bottle, then put plugs back in.
With regards to the single point drain...I'm personally worried about that too.
I e drained my 5.0 MPI using this (pretty sure it all came out) then filled with antifreeze down through hoses on thermostat. This was recommended by local mercruiser dealer. Still a worry....had -5 for last few days here.
Being used to the old carb and good old drain plugs, it's fairly new to me and they aren't cheap to replace. Haha.
 

alldodge

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I would suggest not fogging, it will be fine. Pull plugs as QB mentioned if you want to go the extra
 

tpenfield

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I used to do the auxiliary fuel tank and mixing as Bt Doctur explained. Basically, you are running a 10% mix of 2-cycle oil in the fuel for about 10 minutes. I changed my technique in the past few years, since I empty the fuel tank for winter. Now, after emptying the fuel tank, I just take 4 gallons of the fuel, add about 1/2 gallon of 2-cycle oil and the recommended amount of stabilizer and add it back into the fuel tank. . . . then I run the engines with that mix for the 10 minutes or so.

When I start up in the spring, the engines have some extra lubrication until I add more gasoline to the tank.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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I too would worry about the single point drain.

I also believe fogging isn't required
 

muc

"Retired" Association of Marine Technicians...
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Jul 7, 2004
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2,189
You might want to see what Service Manual #51 says.
You have an EC engine. They are different and have some expensive parts in them.
We are seeing most of the failed/plugged injectors are coming out of engines that didn't have the 2-cycle run thru them each year.



In a 23 L (6 US gal) remote fuel tank mix:
a. 19 L (5 US gal) Regular unleaded 87 octane (90 RON) gasoline
b. 1.89 L (2 US qts) Premium Plus 2‑Cycle TC‑W3 Outboard Oil
c. 15 mL (0.5 fl oz) Quickstor Fuel Stabilizer

NOTICE
Running out of fuel can damage catalyst components. Do not allow the fuel tanks to become empty
during operation.
 

alldodge

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We are seeing most of the failed/plugged injectors are coming out of engines that didn't have the 2-cycle run thru them each year.

What is different in these injectors and the ones Mercs been using for prior years. Haven't heard much of anything about motors not running correctly due to clogged injectors. All cases I've seen on the net and others is because crud managed to get past the filter. Is this due to a new style injector which gets clogged up if its not lubricated with some oil?
 

QBhoy

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Mar 10, 2016
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Mmm. 2 stroke through a fine tuned injector doesn't sit well with me. That and the iridium plugs....
If I was putting the 2 stroke in, it would be by that means. Just in through plug ports and turn her over slowly to get the length of the cylinder.
Just my thoughts. Each to their own.
 
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