Fogging MPI

[High Cs]

In an earlier post I asked what the procedure was to fog my engine (Mercruiser 7.4 MPI) and Don S. graciously provided the link to Mercruiser's service bulletin explaining how this should be done.



I followed the procedure exactly as shown with one exception: Instead of using Quicksilver Fuel Treatment and Stabilizer I used EZ-to-Store/Start stabilizer. Other than that I followed the directions exactly as shown.

I was expecting to see lots of smoke but saw none. After running the engine at 1300 RPM for 5 minutes and ending the procedure I could see that the engine used very little of the "formula". I haven't tried to figure out how much actually entered the system, but I am now doubting if it ran long enough to get through the system. Should I be concerned?

 

[Don S]

Re: Fogging MPI

One thing they fail to mention in that bulletin is to install a NEW (Empty) fuel filter element before you fog. Then use the squeeze bulb of the outboard tank to prime the filter and the fuel system. Then start it and run for 5 minutes.
Depending on the type of fogging oil used, it will only smoke slightly more than normal.

 

[High Cs]

Re: Fogging MPI

I did not start with a new filter thinking that I would change it come spring. I like the idea of starting with a new, pre-filled, filter so I might just do this over the way you describe to make sure it gets fogged properly.

Should I change out this *new* filter in the spring?

 

[Don S]

Re: Fogging MPI

The filters only need changed (AND CHECKED FOR WATER) yearly. Best to do it in the fall. That way if there is water in the filter, it gets removed from the fuel system and doesn't set in filter to create rust, along with the knowledge there may be a lot of water in the tank. If the filter is 1/2 or more water, it's time to get the water out of the tank before it corrodes a hole in the tank or causes serious problems with the injectors in your engine.
Look at the winterizing sticky at the top of this forum for what really needs to be done to keep your engine and drive in top working order.

 

[High Cs]

Re: Fogging MPI

Thank you. Looking for signs of water in the system *now* makes sense. It looks like I will be doing this over again - the correct way.
Now that there will be the fogging mix in the new filter will I need to start out with a clean one in the spring?

I have been using the sticky on winterizing and appreciate the effort put into making it available to everyone.

 

[Don S]

Re: Fogging MPI

You don't need a new filter in the spring. After you fog, that mixture in the filter will dilute and burn out in the spring. Where do you keep the boat? K Cove or Bar Harbor?

 

[High Cs]

Re: Fogging MPI

Boat is trailored, inside at Gateway Yacht Condos. Will be slipped at Bar Harbor in the summer.
I looked two years for this boat. Couldn't find a descent one locally. Ended up getting it in Port Moody B.C.

 

[Don S]

Re: Fogging MPI

The Bayliner 2556's are NICE boats. Have wanted one for years.