Fogging oil

[JHZR2]

Hi,

Curious if there is a best practice for using fogging oil. I get the basic premise, but especially if storing with fuel in it, wont pulling the starter cord to move the cylinder also cause fuel to get sucked in, causing fuel dilution of the fogging oil?

Recommendations?

 

[demarpaint]

Originally Posted By: JHZR2
Hi,

Curious if there is a best practice for using fogging oil. I get the basic premise, but especially if storing with fuel in it, wont pulling the starter cord to move the cylinder also cause fuel to get sucked in, causing fuel dilution of the fogging oil?

Recommendations?



If you get a good fog going there really is no need to pull the starter cord to move the piston. Everything that needs a coating of fogging oil got it. Fill the gas tank, add your stabil, then get the engine good and hot, fog it, drop the oil, fill with fresh oil, and put it away.

 

[Donald]

When I use fogging oil in my Mercruiser, I spray 2 cans at once, one down each side of the carb. My goal is to stall it on fogging oil. When I am doing that whatever fuel is being pulled in is stabilized.

 

[JHZR2]

But dont you want to fog and then move the piston so the entire cylinder gets a good coating? What if the engine stopped at TDC, where the volume is the least? There would be a lot of cylinder wall that was missed...

 

[cronk]

I usually just take the plug wire off and just spray down the carb as I crank or pull the engine over. AS long as the choke is open, which it should be, the amount of fuel pulled into the engine is minimal and won't have any ill effect.

If you are working on a 2 cycle engine, do like Donald says and run it through the engine running until it stalls.

 

[Donald]

The best would be to have the cylinder sealed with all valves closed. Thus there would be an oil vapor in the cylinder. Also the less of the cylinder wall exposed to fresh air the better, so TDC would do that. Fogging oil has a tacky component so it should stick to the cylinder walls. But if like my Mercruiser its a V8 engine or more than 1 cylinder it will always be a compromise.

 

[demarpaint]

Originally Posted By: JHZR2
But dont you want to fog and then move the piston so the entire cylinder gets a good coating? What if the engine stopped at TDC, where the volume is the least? There would be a lot of cylinder wall that was missed...


The engine is fogged while running, and smoking like [censored]. The cylinder wall is coated with a film of oil from top to bottom, along with the piston/pistons and rings. Pulling the cord is not needed.

I also add a heavy dose of MMO to the gas and have the engine running on that while fogging it.

 

[JHZR2]

Aaah, got it. Fog when running, not fog the cylinder via the spark plug hole.

Just trying to learn.

Does it make it a lot harder to restart? Will the junk in there make replacement of the oil necessary?

Thanks!

 

[andyd]

Heh,heh, I used to use MMO to fog a running engine. Except most old B+S flatheads will run on it. Now I add a cap full every fill up. and run the carb dry after every use with a shut off. I dont even take the battery out of my sitdown. My junkers start every spring with out drama. Last May, I used 5 differnt tools . I just pulled them out of the shed. All started with out drama.

 

[JimPghPA]

I have always used the spark plug hole to put StaBil foging oil in the L head Tecumseh HM-100 10 HP single cylinder engine on my big generator, and also my small Generac ix2000. And then pull the cord a few times with a clean rag over the spark plug hole. Then put the plug in and pull the cord a little to stop it on a compression stroke so the cylinder is sealed from ambient moisture building up in it, and also the valve springs are not in full compression.

However it does seam that I only get 3 or 4 treatments before the spark plug gets fouled from the oil during the start-up burn off of the foaming oil. So there might be something to foaming when the engine is running?

 

[Donald]

Anything is better than nothing to prevent rust inside the cylinder over a layup. Bar & chain oil has a tacky component and might be good to try. If it was easy to run the engine I would try and stall it on fogging oil. If hard to run the engine, then pull the plug and squirt some fogging oil in.