View Full Version : Fogging the cylinders

11-01-2002, 07:08 AM
Hello All,

The inevitable has come, winterization!!! How critical is fogging each of the cylinders? I am going to fog the engine thru the carb. This is the first year that I am doing this myself. Thought I would give it a try. 4.3L Merc. Thanks.

11-01-2002, 08:06 AM
I don't fog or stabilize the gas, never had a problem. We start boating in March/April.

11-01-2002, 02:10 PM
I would definately fog the cylinders and stabilize the gas.

My logic is as follows: Gas cantains a number of additives and detergents. Detergents are exactly that I personally do not want detergent coming in contact for an extended period with the bare metal parts of my engine internals. Fogging oil is cheap and there's no reason to take an unncesseary risk.

I realize that it's only 4 or 5 months of layup but as gas stabilizer hurts nothing and insures that no gummy buildups occur in your injector nozzles.

In summary - I'd do both because the cost is so low and it's cheap insurance.

- jeff

11-04-2002, 06:18 PM
What JeffJ said 100%...

Blue Thunder
11-04-2002, 07:43 PM
I do both as well. Only problem I have had is the fogger fouling my plugs. Motor ran fine, just no power. Now I make sure I fire them off in the spring with the old plugs, then install new. I have torn heads off engines that were fogged in the fall to find a nice coating of thin oil in the chambers and cylinders.

BTW... JeffJ, is that a pic of your boat as an avatar? I saw one just like that a couple weeks back launching at Anchor Marine on the NE River. Was that you. I believe the hatch was up..:unhappy1:

BT :cool:

11-04-2002, 08:13 PM
BTW... JeffJ, is that a pic of your boat as an avatar? I saw one just like that a couple weeks back launching at Anchor Marine on the NE River. Was that you. I believe the hatch was up..

that was me.... last weekend out for the season.

I've been going to butch's place for about 25 years now. Bought my first boat from him in 78.
he's an interesting guy (nyuk, nyuk). :)

- jeff

Blue Thunder
11-05-2002, 05:19 AM
That's a nice way to describe Butch :yak:

Sweet boat indeed!! We were on our last run of the season as well and eating at the Goose. I'll stop over and say hi next time I see you.

BT :cool:

11-05-2002, 05:49 AM
I will say this about Butch and his boys: they take great care of me. I've been in a pinch a time or two and they dropped what they were doing to help me out.

Plus, their season pass for the ramp @ $200 is a great deal.

Blue Thunder
11-05-2002, 08:29 AM
I'm with you on Butch's boys at the marina... they do a great job and know their stuff. Some of his salesmen leave a little to be desired though.

BT :cool:

11-05-2002, 12:19 PM
I wouldn't go a winter without fogging. It's also the extreme change in temperatures that allow for moisture to build up inside your engine and cause pitting and rust spots on the cylinder walls. Definately the gas additive too and allow the engine to run for some time to be sure the treated fuel is throughout the carburator.
Hell, believe it or not, I fog all my lawn equipment as well. I haven't had to rebuild any carbs and they start fresh in the spring!:laugher:

11-05-2002, 12:32 PM
when I raced my Ducati and used this really vile ELF race fuel (that would peel powder coating off any surface) fogging was necessary after every race weekend. Of course, it was easy to lift the tank off, open the throttle plates and spray the fogging oil into the throttle bodies and turn the engine over by hand....

fog, fog, fog.... and it kills most of the misquitos in early spring when you start it for the first time too!

Triple Trouble
11-05-2002, 07:10 PM
The following is from the Mercury website under outboards.
It might not apply to people with carbs but if you have EFI???????????

Why is Storage Seal Rust Inhibitor not recommended in the newer EFI and OptiMax engines?

A: Storage Seal Rust Inhibitor uses a thick base designed to protect the internal engine surfaces. In some applications we have seen a build up of the thick base inside the injectors, causing the injectors to stick or operate incorrectly. On these models we recommend Quickleen and 2-cycle engine oil as a replacement for Storage Seal Rust Inhibitor. Quickleen is used to clean the injectors. The engine oil lubricates, as well as prevents rust from forming. We continue to recommend Fuel System Treatment and Stabilizer to help prevent the formation of varnish and/or gum in the gasoline. Always follow the storage procedures outlined in your Operation, Maintenance & Warranty Manual or Service Manual.

Storage seal is Fogging oil......


Triple Trouble
11-05-2002, 07:17 PM
Here is what it says about carb motors on the murcury site.

What is the purpose of using Storage Seal in my outboard engine?

A: Storage Seal Rust Inhibitor is a blend of corrosion inhibiting additives designed to coat engine components during engine storage to reduce the formation of surface rust. Use Storage Seal Rust Inhibitor as directed in your owners and operators manual, following the directions on the container.


11-06-2002, 06:01 PM
My father has a small boat with a 2002 350 Mag EFI. He has already winterized without fogging. Would it be advisable for him to simply pull the plugs and give each cylinder a shot of the fogging spray. He was told not to fog the motor the old fashioned way because the fogging oil may damage the fuel injection system. Any advice would be appreciated.


11-06-2002, 06:48 PM
Mike,it certainly could not hurt anything. Remember the whole idea behind fogging is to lightly coat the cylinder walls with oil. This will help so the rings don't get stuck and score the cylinder walls when re-started in the spring...

Triple Trouble
11-07-2002, 04:43 PM
People have been shooting fogging oil down the cylinders for years and they still recommend doing it on car berated motors along with spraying into the carb.
I think what was happening is that people were getting crazy spraying it into the EFI/MPI fuel injection system and they were finding that it was clogging up the injectors. I may be wrong but I can't see why removing each plug and spaying a little in each cylinder will hurt anything. You should bump the motor a few times after spraying it in. I use to use 1 once of 2 cycle oil in each cylinder on my jet ski's to coat the internal engine parts.
Here is a service bulletin that I got some where on how they recommend doing it during your winterization process.

Mercury Service Bulletin No. 2001-8, New Gasoline EFI/MPI Fogging Procudure issued recently. This bulletin announced the new /proper method to fog a EFI/MPI engine. It recommends that 5 gallons of gas (87 octane) is mixed with 64 ounces of Quicksilver Premium Plus 2 Cycle TC-W3 Outboard Oil and 5 ounces of Quicksilver Fuel System Treatment and Stabilizer Concentrate in a 6 gallon remote outboard fuel tank. Disconnect your fuel line from the Water Separator Filter inlet and connect the remote fuel tank to it. Run your engine at 1300 rpm for 5 minutes and then let it idle after before turning off engine. Do not run gas tank dry.

11-08-2002, 07:29 AM
As always, thank you all.

rob vaughn
11-20-2002, 01:39 PM
Have you checked your owners manual? Most engine manufactors do not recommend fogging the motor unless it is stored for 6 months......
I would check your manual to see, but I would put a stabilizer in the fuel.......

11-21-2002, 06:56 AM
Since I`m here in northern Texas, my winter downtime is from early November (I have not winterized yet ) to early March, about 4-5 months usually. I have NEVER fogged any boat engine I`ve owned. I ALWAYS use Stabile (a brand of fuel stabilizer). My winterization procedure consists of adding Stabile to fuel, changing the oil and filter, draining the outdrive oil and removing all water drain plugs from engine. I`ve never had a problem. But, our temps rarely get below 25 degrees at night. My current engine is way more expensive than any I`ve had before. I am seriously considering fogging the cylinders this year. It is an MPI, I was told by a Merc tech to mix gas, 2-cycle oil and Stabile in my fuel filter and run till I see smoke. You can always spray fogging oil into the cylinders, but that doesn`t get a good coat on the upper part of the valves, but it has to be better than doing nothing!

11-23-2002, 11:18 AM
Good question. I am with you DonMan....is it really necessary when the boat is stored inside, still in use into December and maybe even used on a nice January or February day? Really, we did go boating last January....had some unbeleavably warm days this past winter.

496mag HO's.

Definitely stabilize the fuel though AND flush the engine with antifreeze.