To fog or not to fog...

[Red Stripe]

So I made the appointment for weatherization and it is an extra $40 to have the motor fogged. I have never fogged any in the past and I am curious if it is worth the extra money?

[ajcampen]

First set says not worth fogging an engine......Second set says the first set of mechanics are lazy and you always fog.

Talking to my dealer, i basically got him to say that it is difficult to get the fuel line off the barbed fitting which makes it hard to hook up an external fuel tank.

I winterize my own boat. I made a secondary fuel tank to hook up to my cool fuel module last year. I couldn’t get my fuel line off the barb fitting off so I didn't fog last year but I 100% will this year. I just switched my fuel line connections out this weekend to a spin on SAE fitting. Now I can fog my engine very easily. Basically it is just a little bit of 2 stroke oil mixed with gas and fuel stabilizer. While I heat my engine up to operating temp i'll have it hooked up to this external tank. I’ll then shut off engine. I’ll pull my plugs to drain my engine of water. Put plugs back in then pull 5 gallons of -100 degree antifreeze through the engine…That’s it. So yes fog

[akorcovelos]

I have a complete PDF copy of the 7.4/8.2 Mag maintenance manual I can share if that helps. It outlines all the factory maintenance for long term cold storage and winterizing, including "fogging", though it's not really fogging. It's just running 2 stroke and gas through the VST with the main fuel cut off until the engine dies.

[AsLan7]

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I have never fogged any in the past and I am curious if it is worth the extra money?

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I fog to lubricate the injectors as well as the cylinder walls before storing for the winter.

The Merc Fogging procedure for our 2005 with a Merc engine is described below from a Merc TSB. The fogging mixture quantities mentioned are for winterizing large amounts of boats by a marina but you can make your own mix of course using similar ratios. I have always unscrewed the fuel/water separator from the block; dumped some fuel out into a container; poured in a small amount of 2-cycle oil into the water separating fuel filter along with a little ethanol/fuel stabilizer; screwed it back on and ran the engine for 30 seconds.
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Here is the text copied from a PDF file of Mercury's Service bulletin which covers the fogging procedure.

Fogging Mixture
In a 6 US gal (23 L) remote outboard fuel tank, mix:
5 US gal (19 L) regular unleaded 87 octane (90 RON) gasoline.
64 fl oz. (1.89 L) Mercury or Quicksilver Premium Plus 2-Cycle TC-W3 Outboard oil.
5 fl oz. (150 mL) Mercury or Quicksilver Fuel System Treatment and Stabilizer, OR
1 fl oz. (30 mL) Mercury or Quicksilver Fuel System Treatment and Stabilizer
Concentrate.​


New Fogging Procedure

1. Disconnect and plug boat’s fuel line from Water Separating Fuel Filter inlet.

2. Connect remote outboard fuel tank (with the fogging mixture) to the inlet of the Water
Separating Fuel Filter.
IMPORTANT: If the boat is out of the water, follow instructions for running engine on
flush device as found in service manual for the engine being fogged.

3. a. Cool Fuel models: Start and run engine at 1300 rpm for 5 minutes.
b. VST models: Start and run engine at 1300 rpm for 10 minutes.

4. After specified running time is complete, slowly return throttle to idle rpm and shut engine
off.
IMPORTANT: Do not run engine’s fuel system dry of this fogging mixture in the 6 US
gal (23 L) remote outboard fuel tank.​

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[ajcampen]

.

I have never fogged any in the past and I am curious if it is worth the extra money?

.



I fog to lubricate the injectors as well as the cylinder walls before storing for the winter.

The Merc Fogging procedure for our 2005 with a Merc engine is described below from a Merc TSB. The fogging mixture quantities mentioned are for winterizing large amounts of boats by a marina but you can make your own mix of course using similar ratios. I have always unscrewed the fuel/water separator from the block; dumped some fuel out into a container; poured in a small amount of 2-cycle oil into the water separating fuel filter along with a little ethanol/fuel stabilizer; screwed it back on and ran the engine for 30 seconds.
.

Here is the text copied from a PDF file of Mercury's Service bulletin which covers the fogging procedure.

Fogging Mixture
In a 6 US gal (23 L) remote outboard fuel tank, mix:
5 US gal (19 L) regular unleaded 87 octane (90 RON) gasoline.
64 fl oz. (1.89 L) Mercury or Quicksilver Premium Plus 2-Cycle TC-W3 Outboard oil.
5 fl oz. (150 mL) Mercury or Quicksilver Fuel System Treatment and Stabilizer, OR
1 fl oz. (30 mL) Mercury or Quicksilver Fuel System Treatment and Stabilizer
Concentrate.​


New Fogging Procedure

1. Disconnect and plug boat’s fuel line from Water Separating Fuel Filter inlet.

2. Connect remote outboard fuel tank (with the fogging mixture) to the inlet of the Water
Separating Fuel Filter.
IMPORTANT: If the boat is out of the water, follow instructions for running engine on
flush device as found in service manual for the engine being fogged.

3. a. Cool Fuel models: Start and run engine at 1300 rpm for 5 minutes.
b. VST models: Start and run engine at 1300 rpm for 10 minutes.

4. After specified running time is complete, slowly return throttle to idle rpm and shut engine
off.
IMPORTANT: Do not run engine’s fuel system dry of this fogging mixture in the 6 US
gal (23 L) remote outboard fuel tank.​

.

You nailed it! How much gas does your boat use for this process. I was going to get I gallon for my boat and a friend.