How important is it to "Fog" the motor?

[spfortjohn]

I boat in the south we boat March through November and I have always had outboards. We just let the water drain and run it on the flusher every month or so in the off season. I never fogged the motor.

With my new I/O 350 Mag MPI B3, I plan on changing the motor oil, filter and drive oil, replacing the fuel filter and draining the water and putting in my warehouse over the winter, If we get a nice day we might take it out for a run in December or Feb. Should I worry about fogging the motor or not? What about the antifreeze should I suck it up from the foot via the flusher or pour it in the hoses on the motor? Or should I even worry about antifeeze if I drain the water out after use?

I also plan on changing the water pump in the spring so it will not sit and get a set over the winter.

 

[ZZ13]

My 175 Sport is garaged on a trailer in Beaufort,SC. Probably similar winter weather to you. The garage never gets below freezing (of course, rarely does the outside air either). During the winter, I simply roll it out of the garage and start it up on muffs every 4-6 weeks and let it run to temp and then put it back in the garage, if I haven't taken it on the water in more than those 6 weeks. I don't fog (starting every once and a while is intended to keep everything lubed up) and I don't use antifreeze and I don't even disconnect the batteries. Most people here don't even do what I do. They just let it sit until the next time they use it, although most have outboards.

 

[tbirdvet]

I agree with ZZ13. I would skip the fogging or if you want put some Starbrite fuel additive (EZ store/EZ start) with built in fogging oil

 

[northern]

In the 10 years we have had inboard cruisers we have never fogged an engine. We also have a jet boat with a 350 that we store outside in the winter and never fogged. No problems so far. One year I had some one start my engine every week all that did was burn a lot of fuel as best as I could tell.

 

[rcknecht]

I don't fog my fuel injected motors... Its too much trouble... Change the plugs, oil, pumps, etc... IMO its more important to use your your boat... If you let it sit a long time, you more likely to have trouble...

 

[ZZ13]

I am kinda with Northern. I think all this winterizing stuff is way over analyzed and over specified. I think the marinas and pink manufacturers are preying on fear, uncertainty and doubt to make lots of money off of us. Just get the water out of the cooling jackets so freezing won't crack anything and probably we'd be good to go. But what do I know.

 

[northern]

The cruiser is on the west coat it stays in the water all year. It has got to 15F a few times. Never had any problems with freezing as we have two 100 watt heaters on the boat that keep it above freezing. The jet boat sits in the back yard covered. It goes to minus 40F some times. I drain the engine by opening a hose connect at the low point then blow all the water out with a shop vac until no more water comes out the exhaust. No engine damage so far. Jet boat is a 2008. Jet boat has a anti freeze cooling system. I take the zinc corrosion anoid out and when blowing with the shop vac I make sure no water is coming out where the zinc goes.
Booth boats start fine in the spring.

 

[moparlvr4406]

Doesn't the "fog" mainly add to cylinder lubrication to protect the rings from rusting to the cylinder walls rather than protect anything from freezing:huh:
I would think this would be VERY important on an engine that would be static for months.

 

[Lazy Daze]

Yes, to the above.

Any engine should be fogged when it will not be used for a while. Weedwhacker, lawnmower, whatever. Will it immediately kill the engine if it's not fogged? Doubtful. But over time, it will have an effect as, at a minimum, the rings won't seal as well against the cylinder wall. Why skimp out on about 50 cents worth of product?

I've seen relatively new boats that sat on a trailer (inland - not even coastal) for 6 weeks. When I started them up, you would be amazed at how rusty looking the water was coming out of the exhaust. Not pretty.

 

[spfortjohn]

Still on the fence. I am going to do all the maint issues such as Oil, Filter, Gear Lube, Fuel Filter, Water Pump, Grease the fittings, pull and lube the spines on the prop shaft, put stabl in the fuel, I might run antifreeze through the motor but the fogging is a pain as I do not have a seperate tank and fittings. Merc does not make it easy to fog with the darn cool fuel system.

If we had a decent shop on the coast that we could make an apointment with and drive in and have them do it while you wait that would be great. I do not want my boat to sit outside at some dealer untill they have time to do it.

 

[moparlvr4406]

Yes, to the above.

Any engine should be fogged when it will not be used for a while. Weedwhacker, lawnmower, whatever. Will it immediately kill the engine if it's not fogged? Doubtful. But over time, it will have an effect as, at a minimum, the rings won't seal as well against the cylinder wall. Why skimp out on about 50 cents worth of product?

I've seen relatively new boats that sat on a trailer (inland - not even coastal) for 6 weeks. When I started them up, you would be amazed at how rusty looking the water was coming out of the exhaust. Not pretty.

100% agreed ....anytime rust forms in a cylinder it WILL shorten the lifespan of the engine

 

[CliffA]

Still on the fence. I might run antifreeze through the motor but the fogging is a pain as I do not have a seperate tank and fittings. Merc does not make it easy to fog with the darn cool fuel system.

i have never fogged any of the engines on any of my equipment or vehicles so i have never done it, but if you do decide to fog the cylinders can you not just pull the spark plugs and spray the fogging oil directly into the cylinders through the spark plug hole?....i know that would take a little time but it may be easier than trying to set up separate tanks and fittings...it would be a good chance to look at the condition of the plugs to see any signs of potential problems...

 

[Lazy Daze]

Yes, you can go directly into the cylinders with the spray or even just a teaspoon, or two, of motor oil. This tends to be more of a pain (usually) because of access to all the plugs on a inboard (not all) is impeded with the exhaust manifolds in the way. It works good on a lot of OB's that have direct access to the plugs.

 

[douglee25]

It does have a purpose to keep the cylinder walls lubed while in storage to prevent surface oxidation. I have to say the whole business using separate tanks for the injected engines is way beyond most boaters. I can't believe Mercury actually puts that info in their manuals. They should have come up with a much more user friendly way to accomplish this.

Doug

 

[dpmulvey]

Fogging will destroy Iridium plugs. Beyond that....have fun.

I have always fogged marine carbed engines when I lived in the NE. It was too easy not to.

 

[Groucho]

What does the owners manual say??
I don't ever recall seeing Fogging as a practice.

 

[Presentation]

The owners manual and maintenance manual (factory) say to run a mixture of 2 cycle oil, and stabilizer through the engine at 1300 RPM for five minutes. NO SPRAY, NO GIMMICKS, NO BUTS. It is very specific on how to do it, and is the one and only approved way to fog an MPI. To do anything else is to walk on the dark side, per Mercruiser.

I do as Mercruiser says, but you folks can do what you want....they are your engines after all.

Scott, have you ever gone to West Marine and seen the kit they sell for winterizing the engine with the pink antifreeze?

No such kit exists that I can find for correctly fogging an MPI sterndrive engine.

If you put a kit together like you built, put some step by step instructions in the kit such that all the person needs is gas and oil + your kit I would buy one. I bet many other boaters would buy it also.

Jim (site owner) could give you some tips. E-bay could be one sales avenue for you.

I’m totally serious Scott, your home built setup is very good and the need / demand for this kit is there.

 

[Westie]

Scotts manual has different instructions then mine but we have different engines too.
There are no kits needed to preform the fogging on the 7.4 MPI engine.
Here is what the factory service manual says

6. Close the fuel shut-off valve, if equipped. If no fuel shut off valve is present, a suitable
method must be employed to STOP the flow of fuel from the fuel tank to the engine
before proceeding.
7. Prepare fuel system for extended storage as follows:
a. Allow engine to cool down.
b. Remove the water separating fuel filter.
c. Pour out a small amount of fuel into a suitable container, then add approximately 2
fluid ounces (60 ml) of Quicksilver 2-Cycle Outboard Oil to fuel in the water separating
fuel filter.
d. Install water separating fuel filter.
e. Start and run engine at idle speed until the water separating fuel filter and fuel injection
system are empty and engine stops.
f. Remove and discard water separating fuel filter.
g. Install new filter

Note that is says to run the engine until it stops due to fuel starvation. This ensures that there is no more fuel in the system that will sit there while stored.

Simple to do and no extra "kits" required.

 

[Summer Fun II]

Do you guys fog your car/truck engines when you don't use them for months ??.

I don't and my 1999 car has only 87.000 mi's and it runs great. :smt001

If you live around saltwater then YES. :thumbsup:

 

[Lazy Daze]

Do you guys fog your car/truck engines when you don't use them for months ??.

I don't and my 1999 car has only 87.000 mi's and it runs great. :smt001

If you live around saltwater then YES. :thumbsup:

I do! :smt001

Keep in mind, "runs great" doesn't necessarily mean "runs as good as it should". Think of it this way... are you doing any damage by fogging it? Could damage happen by not fogging it? Bare metal (cylinder walls, rings, etc) rusts. Putting a light coating of oil on it dramatically decreases that.