winterizing a fuel injection system

[guppy]

Since you can't "fog" fuel injection in the traditional method, What ratio do you use30:1 or 50:1? I have another portable tank I can hook up to the fuel system . I would like to get it right since this boat will be sitting for 3 or 4 months

 

[bondo]

Ayuh,.... I use whatever mix is in the nearest 2-stroke outboard fuel tank...

Use whatever mix you'd like,... I don't think even 16:1 would hurt anything....

 

[RicardoMarine]

That is true. Fogging is done to carbureted engines.
What's done to an FI engine is actually fuel stabilizing.

Many will stabilize their main fuel tank just as you normally would, and just prior to your last outing or gentle trailer ride (to mix it up).
You'd then remove the fuel filter cartridge, empty it, add your oil enriched fuel mixture directly into the cartridge.
(this can take the place of an external fuel tank with oil enriched fuel)

You would then reinstall the cartridge and run the engine long enough for this "fat mixture" to reach the FI system.
The stablized main fuel will reach the filter cartridge.

It helps to fire up and warm the engine prior to this, IMO.

The rich oil mixture should not harm or foul your spark plugs during low load/low heat operation.
IOW, you should be OK come spring time after the first fire up.

However, this is not actually "fogging" (as in cylinder protection) in the usual sense.

BTW, you could possibly fog an FI engine if the fogging solution was introduced down-stream of the air sensors.
It's the sensors that we need to be careful with.

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[Blurry]

mercruiser does have a procedure for fogging the efi and mpi motors.
here is a pictrue of the service bulletin. they call it fogging, so i guess it is.

 

[RicardoMarine]

Blurry, I guess that I'm old school when it comes to certain things.

Fogging to me, back when I learned the procedure in the 60's, was done with oil added directly into the primary throats of a carburetor. Today we have much better fogging oils.

Split or dual plane intake manifolds must be fogged equally, or we miss half of the cylinders.
The objective was to do this at approx 1,200 rpm, and to cut the ignition source while the fogging continued.
The goal was to wet the cylinder walls, valve seats and stems just prior to the rotating assembly coming to rest, and without combustion burning the fogging oil.

When a FI or an MPI engine is shut down, the fuel delivery discontinues.
Where's your cylinder wall protection (from the oil enriched fuel) that would otherwise be there had the old school procedure been used?

But as we know, terms become bastardized over the years, such as an engine often being called a motor today.
If Merc wants to call this fogging, well........ we'll call it fogging!



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[kghost]

The proceedure posted looks like a stabilizing vs fogging even though merc calls it such.


This is my take on fogging a engine for storage.

first there are two types of storage, Long term and Short term.

For our purposes we will stick with Short term.

Fogging is a crucial part of winterizing a 2 stroke engine.
The crank shaft and recripricating components are directly behind the intake manifold. The recipricating assembly typically uses needle bearings NOT LEAD BABBIT TYPE used in 4 stroke motors. It is exposed to atmosphere for the most part thru the carb(s).

The oil/gas mixture used with a 2 stroke the oil seperates and clings to the bearings and other friction surfaces.

When foggining a two stroke the fogging oil sticks to all the componets inside the crankshaft and does also get pulled into the combustion chamber(s).

When doing this it is best to fog after a motor is warmed up and the fuel line is disconnected or gas flow is shut off and fog until the engine runs out of fuel (choking to use as much of any left over fuel as possible).

The fogging agent clings to all surfaces and protects them from moisture, The needle bearings become or can become somewhat magnetic and very very clean after normal use and because of this they attrack moisture in a seriuos way and will corrode if not protected.

In the 15 + years I have winterized boats I rarely fogged a 4 stroke motor. I did upon customer request but not otherwise.

Is it a good thing to do to a four stroke, Yes
Is it necessary? in my opinion not for short term storage.

Again only my opinion!!

 

[RicardoMarine]

Fair enough, and I can't disagree with you for short term storage!

However.... (big however here)... whether for short or long term, if the intent is to protect cylinder walls, valve seats and valve stems, how can we expect a protective solution to perform it's task if we allow this mixture to combust?
I know.... not all becomes combusted.

There may a way to "Fog" an MPI engine, if we could somehow eliminate the risk of getting this solution into the air sensing circuits.
In order to do this, the solution would need to be introduced into the system past these sensors.
However, I've not tried this.


As for old school.... here's what I belive to work best, and again, if the intent is to protect cylinder walls, valve seats and valve stems.
I've always believed that fogging a cold engine is best, as to help the fogging solution adhere better.
Either or.... your call!
At approx 1,200 rpm, I introduce the solution equally into each plane (i.e., both primary throttle bores).
As I proceed and near the end, I cut the ignition source as to prevent further combustion.
I continue the fogging until the rotating mass comes to rest.
Engine fogging can be done in as little as 10 seconds when done correctly.

Wrap her up, give her a kiss, and say good night to her.

Of course this would include all other winterizing measures prior.


No argument here.... just say'n.


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Another interesting topic (often debated) would be squirting oil into cylinders thinking that the piston landings will wipe the cylinder walls with oil. This old idea came about years ago during the days of vertical cylinder wall inline engines fitted with flat deck pistons.
This works well for vertical cylinder engines w/ f/t pistons....., but not so well for V engines.

With many engines being V engines today, gravity prevents this from working as well as some believe that it does.
The oil has a tendancy to quickly pool at the low side of the piston deck or ring landings, preventing an even wiping of the cylinder walls.
Add dished pistons into the mix, and it becomes even less valuable, IMO.

I know..... that's another topic for another day.




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