MPI Fogging - Fuel Line Question . . .

[tpenfield]

Today I am going to fog my Mercruiser 7.4 LX MPI engines (see sig. below) and I was wondering about the fuel line considerations, having to disconnect and re-connect things.

Presumably, each year, I will have to disconnect and re-connect the main fuel lines to connect the temporary line for the "fogging cocktail mixture". In my previous experience of disconnecting fuel lines from the barbed fittings, it is quite a task and often places wear and tear on the fuel line.

I know that there are a fair amount of 'regulations' and/or 'safety standards' applying to marine fuel systems, but I am wondering if there is a more permanent way of having a fuel line for the fogging oil and avoid the annual removal/re-installation of the primary fuel line. ????

Something that would meet safety standards, etc. . . . ,maybe like an auxiliary tank setup???

 

[Fun Times]

Re: MPI Fogging - Fuel Line Question . . .

Yes it can be difficult to remove at times, But if you carefully lube the inside of the hose it should be much easier to remove the next time.

Twisting the hose back and forth should help today.

Good luck.

 

[Bondo]

Re: MPI Fogging - Fuel Line Question . . .

Today I am going to fog my Mercruiser 7.4 LX MPI engines (see sig. below) and I was wondering about the fuel line considerations, having to disconnect and re-connect things.

Presumably, each year, I will have to disconnect and re-connect the main fuel lines to connect the temporary line for the "fogging cocktail mixture". In my previous experience of disconnecting fuel lines from the barbed fittings, it is quite a task and often places wear and tear on the fuel line.

I know that there are a fair amount of 'regulations' and/or 'safety standards' applying to marine fuel systems, but I am wondering if there is a more permanent way of having a fuel line for the fogging oil and avoid the annual removal/re-installation of the primary fuel line. ????

Something that would meet safety standards, etc. . . . ,maybe like an auxiliary tank setup???

Ayuh,.... Just fill the filter with yer cocktail, 'n run it...

If you insist on riggin' a remote tank,...
Find yerself a hose pick, which is basically an ice pick, that's bent...
With it, ya loosen the hose clamp, slip the pick in under/ 'tween the hose/ barb, 'n pry slightly, removin' the hose, easily...

 

[90stingray]

Re: MPI Fogging - Fuel Line Question . . .

Cant you just fog thru the air side of your engine. What if you just shut her down, then pull the plugs... and blast some into the cylinders. I have never done a mpi engine... just thinking out loud.

 

[boat127]

Re: MPI Fogging - Fuel Line Question . . .

Can't fog thru throttle body on mpi engines. Due the way intake is installed

 

[Don S]

Re: MPI Fogging - Fuel Line Question . . .

Ayuh,.... Just fill the filter with yer cocktail, 'n run it...

If you insist on riggin' a remote tank,...

That doesn't work very well, as fuel is used, the mixture gets diluted with the new fuel coming in the top of the filter. Soon you are back to straight gas. That is why you hook up a tank, so you can run it for 5-10 minutes and get things fogged right.

Ted, look around at some plumbing stores. Some barbed fitting are smooth on the end with just a single rounded barb on the end of the fitting. These work perfect where you have to remove the line once a year without damaging the hose.

http://www.iboats.com/UNIVERSAL-FUE...8797989--session_id.438769944--view_id.927837

 

[Capt Ken]

Re: MPI Fogging - Fuel Line Question . . .

You do not put fogging oil through the fuel system. You put fuel with stabilizer through the fuel system. You spray fogging oil through the intake, then remove the spark plugs and spray fogging oil into the cylinders. Any left over spray is used to spray on the engine.

 

[Don S]

Re: MPI Fogging - Fuel Line Question . . .

You do not put fogging oil through the fuel system. You put fuel with stabilizer through the fuel system. You spray fogging oil through the intake, then remove the spark plugs and spray fogging oil into the cylinders. Any left over spray is used to spray on the engine.

It seems Mercruiser and Volvo don't agree with you Ken.
Do to manifold design, through the fuel system is how it's been done for years. Here are service bulletins explaining how it's done.
Note that both are using outboard oil as the fogging oil.

View attachment Volvo MPI Fogging.pdf View attachment Merc MPI Fogging.pdf

 

[tpenfield]

Re: MPI Fogging - Fuel Line Question . . .

Thanks for the replies folks . . .

I pumped all of the remaining fuel out of the tank (20 gallons +/-) (160 gallon tank, so it was fairly empty). I put 10 gallons in the Ford and 5 gallons in the Buick. I got about 2 gallons to make the 'MPI Cocktail' and 3 gallons for the lawn mower/snow blower.

I considered just filling the fuel filter with cocktail, but that would be no picnic either. Plus it would probably need more than just a filter full to do the fogging.

So, I am still wondering if there is a way that would be regulatory & standards compliant to get an auxiliary tank configured into the fuel system??? Then, I could just fill the Aux tank with cocktail and flip a couple of valves or something to do the fogging.. . . .

 

[Don S]

Re: MPI Fogging - Fuel Line Question . . .

Kind of over engineering a process that takes 15 minutes one time a year aren't you. Loosen the hose clamp and pull the fuel hose off the smooth fitting. You start adding valves and a lot of fittings and you are building in possible air leaks and running problems.

 

[tpenfield]

Re: MPI Fogging - Fuel Line Question . . .

Well I finished the fogging of the engines this afternoon. Below is a video that I made of the fogging.

I mixed 2-1/2 gallons of fogging mix, but only used about 1 to 1-1/2 gallons of it. Ran the engines for 15 minutes each. So, I am wondering what to do with the gallon or so of fogging 'cocktail' ???? I suppose that I could run it through the engine in the Spring . . .

Taking the fuel line off was OK, but not great. Those barbed fittings get a nice grip on the fuel line and they do not give up easily.

Oh well, it is done for the year. Maybe I can grease them for next year, as suggested.