Fogging my motor and getting the plugs out

[skategoat]

I own a 50hp 4-stroke Mariner. First time winterizing it myself so I have a couple of questions.<br /><br />First, the fogging spray I bought tells me to spray into the carb until the engine stalls. What makes the engine stall? The fog oil? I'm thinking the engine will just keep running.<br /><br />I tried to remove the plugs to spray into the cylinders but could not find a socke to fit. My 5/8 inch socket is too small but my 13/16 inch won't fit into the recess so I don't know if it's the right size. Can anyone confirm that 13/16 is correct and if so, do I need some sort of thin-wall socket?<br /><br />Thanks,<br /><br />Henry in Canada

 

[HuronBob]

Re: Fogging my motor and getting the plugs out

Any chance this is a yamaha powerhead??? If so, my 40 hp yamaha 4 stroke needed an 18mm socket for the plugs....(thin wall, not much room in there!)<br /><br />Just an idea....<br /><br />and, yes, the fogging oil will cause the engine to stall...<br /><br />bob

 

[dajohnson53]

Re: Fogging my motor and getting the plugs out

RE: fogging.<br /><br />I've not fogged a 4 stroke, but I've done a few 2 strokes. The instructions I've read in various places says to use something like a can for every two cylinders. That's a huge amount of fogging oil! But even though I haven't used that much, this leads me to believe you need to squirt a bunch in. If you just start squirting it in, you can get the engine to stall out pretty quickly - in just a few seconds. I've always thought it was good to fog at least for a few minutes so I tend to squirt at a lower rate, or quick short bursts so the engine falters but doesn't kill. You'll know it's being fogged because it smokes a lot. <br /><br />For my little single carb kicker I just do this technique for a couple of minutes, then turn up the volume of the spray and kill it. Then I remove the plugs, squirt a whole bunch into the hole, crank it over a few times and replace plugs.<br /><br />For the 3 carb V6 main engine, I hold two cans of fogging oil. Being highly coordinated, I use both hands to go from carb to carb fogging just on the edge of killing it until both cans are almost gone. That's a lot of fogging, believe me. I then pull the plugs and empty the two cans into the 6 cylinders, turn it over a few times, replace plugs, etc.<br /><br />By the way - in reference to the little plastic straw that you could use to direct the spray: don't bother using them. I've found that fogging oil spray nozzles tend put out a very thin, strong, directed stream. Therefore I don't use the plastic straw attachment. It only falls off and gets in the way and has the risk of being sucked into the engine. Mostly though, they just get in the way and/or fall off. My technique is very slightly messier, but I really don't worry about a little errant oil sprayed onto the engine.

 

[KCLOST]

Re: Fogging my motor and getting the plugs out

I really don't think spraying that much fogging oil into the carbs is really necessary.... Reason being, all you are really doing is throwing in extra oil to get sucked into the crank case... Which is really the only area that the fogging oil is doing any good. It's being burned off after going into the cylinders. But we are already sucking in oil with the fuel so it's lubricated sufficiently anyway. A little won't hurt, by any means, actually will help. But a couple of cans is overkill IMO... The crankcase will only hold so much oil on it's surfaces, after that it goes into the cylinders where it is burned away.<br /><br />Spraying a good amount into the cylinders is a need however for outdoor storage.

 

[rschnack]

Re: Fogging my motor and getting the plugs out

Check with your owner's manual!. I have a 2001 50 hp Mercury four stroke. The service manager at the marina where I bought it said that Mercury told him to never fog these motors. Apparently the fogging oil base is too thick and does not allow the valves to seat for a while after start up, causing damage to the valves. This is a problem in 4 stroke outboards since they run cooler than other 4 strokes. Last year the dealer mixed up a special brew of gas, 2 stroke oil and stabil to run the motor on before storage. This year I contacted Mercury directly. The service rep told me to not fog the motor or run the mixture through the carbs. He said to follow the directions in the owner's manual, since their recommendation is based on much testing. The manual recommends simply putting a small amount of motor oil in each cylinder and turning the motor over by hand to coat the cylinder walls (plus the usual: stabil in the gas, changing the oils, etc.)<br />RCS

 

[KCLOST]

Re: Fogging my motor and getting the plugs out

I messed up, kinda.... You have a four stroke!!!!!!<br /><br />Don't need fogging oil... You have oil soaking the crank case, and those carbs aren't designed to have oil inserted into them....

 

[skategoat]

Re: Fogging my motor and getting the plugs out

Woah, glad I read this. I thought for sure the manual told me to fog but I will double-check.<br /><br />Thanks,<br /><br />HK

 

[vg]

Re: Fogging my motor and getting the plugs out

Interesting topic.<br /><br />My motor is going to stay mounted on my boat outside and it will get to sub-freezing conditions before too long from now.<br /><br />I just purchased a new left over 2004 Mercury 15hp 4-stroke outboard (standard model) earlier this year and now my dealer is telling me to use fogging oil to fog the engine. When I told the mechanic that the manual does not state that, but rather use a small amount of engine oil in each head, the mechanic's response was (paraphrasing):<br /><br />"Just because the manual does not say to use fogging oil, that does not mean that it can not be used. We have been foggin 4-strokes for 25 years."<br /><br />I then called Mercury up directly (regarding my specific type of 4-stroke) and they simply said that, <br /><br />"Fogging oil was not necessary."<br /><br />Note, the mercury rep DID NOT say that fogging oil can not be used, he simply said it was not necessary.<br /><br />Maybe it makes no difference (for my specific type of 4-stroke). Maybe it's an added waste of money and time to fog this motor. Maybe what little difference it has on the life of the motor will never be noticed. Heck, I don't know. Don't ya just love these little differences of opinion (dealer vs. mfg). I guess I will not use fogging oil. <br /><br />Any one care to comment further on this topic?

 

[MrBigStuff]

Re: Fogging my motor and getting the plugs out

On all my 4 stroke engines (cars, marine), instead of fogging, I simply pull each plug and squirt a modicum of oil into each cylinder. Then turn the engine over a few revolutions by hand to distribute the oil and viola! done.<br /><br />The idea is to coat the rings and cylinder walls to limit rusting during storage. I use the same set of plugs to start the engine in spring and once the oil has burned off, put in fresh plugs.

 

[Silvertip]

Re: Fogging my motor and getting the plugs out

Fogging a four-stroke has a major risk of hydrolocking one or more cylinders. Besides, fogging oil does not get into the crankcase (thats where engine oil lives) and it doesn't get into the valve train as that too is lubricated with engine oil. The only place fogging oil can reach going through the carbs is the intake manifold, then directly into the combustion chamber, burned, and expelled through the exhaust. If you kill the engine, all you are protecting is the cylinders and running the risk of the aforementioned hydrolock. Simply warm the engine just before storage. Stop it, remove the plugs spray a fine mist of oil (fogging oil if you wish), into each cylinder, then rotate the engine a time or two by hand. Insert the plugs and put the engine to bed. In the spring, pull the plugs, rotate the engine with the starter to expell excess oil. Insert the plugs and you are good to go.

 

[vg]

Re: Fogging my motor and getting the plugs out

MrBigStuff & Upinsmoke,<br /><br />Thanks for the info. Before reading your replies I had already shot some fogging oil into the heads of the cylinders only....nothing in the carbs. Come spring I'll go ahead and turn the motor over a few times and put in some new plugs. <br /><br />Common sense sort of told me to not go ahead and get crazy with the fogging oil as it was never mentioned in the Mercury manual.<br /><br />Just out of curiosity, could one just as well have used WD40 to shoot into the cylinder heads? I know I used to do that on my old Honda 4-stroke many years ago for storage. The manual only says to shoot the cylinders with some motor oil.

 

[Silvertip]

Re: Fogging my motor and getting the plugs out

It would probably be ok but there are much better lubricants than WD40. Stick with the fogging oil and you'll be ok.

 

[MrBigStuff]

Re: Fogging my motor and getting the plugs out

Yeah, WD40 is a water displacement (hence the WD) and very light lubricant. Oil has more staying power over the long term and that's what you want- something that will stay put for several months.