Fogging an MPI Engine?

[MAKC]

Ive been winterizing my 2003 Sundancer with the 5.0 MPI engine and i have a question. How do i fog the engine? Ive read through the service manual and it doesnt say how to (or even TO do it for that matter). Do i just pull the air cleaner off and spray into the intake? Ive drained the water from the block and am ready to put the "ear muffs' back on the outdrive to pull the anti-freeze into the engine. Is there anything besides just putting several gallons into a 5 gallon bucket and running the engine to siphon the anti-freeze in there? The winterizing check list from Stroemeister was awesome but this is the first time ive ever tried to winterize my boat. Thanks in advance!

Edit: I should also add that my boat will be stored indoors in a climate controlled garage (no lower than 45-50 degrees even in the dead of winter).

Mike

 

[jsea558]

Hi Mike, i have a 7.4L MPI but the procedure is probably the same as yours. Someone told me that spraying directly into the intake can ruin one of the sensers. My Merc. maintenance manuel says to use 2 cycle oil to fog the engine. Its done by stopping the flow of fuel from the tank, either by a shut off valve or some other means.( i disconnect the fuel line from the tank, or carefully pinch it off.) Then take off your fuel/water seperating filter, and pour out a couple of ounces of fuel into a container. Then add 2 ounces of 2 cycle outboard oil to the fuel filter and put it back on the engine. Make sure any spilled fuel is cleaned up and the blower run until there is no fuel smell. Start and run engine at idle until it stops. Then remove fuel filter,and discard. Install new filter, with new fuel and stabilizer, do not put it on dry! You could run the risk of burning up your fuel pump. I also pull the spark plugs and spray fogging oil into the cylinders, and reinstall the plugs. As far as the anti-freeze, West marine or Boaters World has a kit to facilitate running anti-freeze through the engine. Its fairly inexpensive. I believe your engine has to be fully heated to temperature so the anti-freeze runs all the way through the engine, but i could be wrong. I know your boat will be inside, but the anti-freeze will keep it from rusting up inside, so it can't hurt to do it. I hope this helps you. Good luck. Jon

 

[wish2fish]

This may be a little latel, but do you have to use fogging spray any more? My manual say to use a mixture of Gas, Fue Stabilzer and 2 cycle outboard oil. Run the engine for 10-15 minutes the stop. I'm assuming the 2 cycle oil will coat the linings of the cylinder walls. They call it a fogging mixture. Recipe is: 5 gal of gas, 5 oz fuel system treatment and stablizer, 2 qts of Premium 2 cycle TC-W3 outboard oil.

you probably wouldn't have to make this much as you have to run the engine at 1300 rpm for 5 minutes.

anyone have comments on these directions?

 

[Dave S]

JSEA's procedure of pouring a mixture into the fuel filter is the one my dealer uses to fog engines. There is also a fuel stabilzer available from West Marine that alledgedly eliminates the need to fog your engine.

 

[MAKC]

i ended up taking the fuel/water seperating filter off, pouring half of the fuel out of it into a gas can, filling it back up with 2 cycle oil, and putting it back on the engine. I then ran the engine long enough to suck the anti-freeze into the outdrive (5 gals) and shut it all down. It worked great! Just be careful to clean up any fuel spills in the bilge and vent that baby GOOD before you start the engine to fog it and fill it with antifreeze.

 

[boatrboy]

JSEA's procedure of pouring a mixture into the fuel filter is the one my dealer uses to fog engines.........

Same proceedure I use too.

Mark

 

[kyle f]

I was told by me dealer that it was easiest to just use the spray into the Throttle Body. Thats how they said they do it, but that with the MPFI, it wouldn't die. Just do it long enough that you are getting a really good smoke show out the prop, and shut her off. Ofcourse, this should be one of the last steps done. You should have already put your fuel stabilizer in so that while doing this, it will pump it into the rest of the system.

This spring, I pan on the first trip to be a short one, using up the gas left in the tank. Then filling it up again, running it out, then running a fulll tank treated with STP complete fuel system treatment to help break down anythign that may set up.

 

[boatrboy]

I was told by me dealer that it was easiest to just use the spray into the Throttle Body. Thats how they said they do it, but that with the MPFI, it wouldn't die. Just do it long enough that you are getting a really good smoke show out the prop, and shut her off. Ofcourse, this should be one of the last steps done. You should have already put your fuel stabilizer in so that while doing this, it will pump it into the rest of the system.....

FWIW - I was under the impression that fogging that way may harm some of the sensors. I did not look this up today but, I believe that if you check your Merc manual, it will outline the procedure mentioned earlier (making a mixture in the fuel filter). I also received this advice from a Merc dealer's service manager. I would just double check with you service manager or a master mechanic there.

Mark