Properly Fogging a Suzuki df250

[Jake 99]

All,

Apologies if this has been discussed, but I have searched this and other forums to find an answer and haven't found anything definitive. I'm in New England, about to settle in for the winter. Over the past few years, I have slowly begun doing all the maintenance on a 2015 suzuki df 250 outboard, and for the most part, it's easy. I am about to do the lower unit, oil change etc. for winter layup. Now, the very expensive yard where I used to have it serviced would inject a winter mix into the engine, but they never told me what they did, only that "the fogging oil will quickly burn off in the spring - no worries there." So my questions are: do I fog the intake? (I believe the answer there is NO), do I put oil in the spark plug holes and turn the engine over? (I believe the answer is YOU COULD, BUT NOT NECESSARY), do I run the motor on a mix of gas and fogging fluid, then shut down once it begins to smoke (I BELIEVE THE ANSWER IS YES, BUT HOW MUCH FOGGING FLUID TO ONE GALLON OF GAS?) Now, one interesting approach I have read is to add one oz of 2 stroke oil the the fuel water separator and run the motor until it smokes, then shut down. While that would be simple, I'm not sure it is the best approach. I am worried about the effect to the engine internal sensors. My plan is to buy a portable gas can, add the appropriate ratio of fuel to fogging oil, attach it to the intake on the fuel water separator, run the engine till it smokes, shut it down, then re-attach the gas tank line to the fuel water separator.

Opinions?

 

[vroom ZOOM]

I have a DF200 (v6) similar engine as yours, yours has the vvt. All the sensors are in the top of the silver intake air collector, between the two throttle bodies. So unless you fog it through the iac, (big no no) there really aren't any sensors from there on. Having that said, the design of the air collector doesn't quite lend itself to being fogged. I tried foggin mine, but it would not pull the oil through, it would just settle on the air collector and not go through the cylinders. So you could, but it doesn't really work that great. Maybe it was due to the oil being too thick, I will try a thinner one later. What I would recommend you do, and this is what most marine engine manufacturers do, is to pull the plugs, spray some fluid in each cylinder, and turn it over with the PLUGS OUT, or else you risk hydrolocking your engine. Disconnect the coils when cranking, and pull the safety switch, or you could cause some electrical damage to the ecm. However, not really necessary to fog a four stroke. it is more of a 2 stroke thing. As for fuel stabilizer, and additives, have a look at this video:

. My best recommendation is to fill your boat's tank full of ethanol free super gas, run the engine long enough to get the fuel in the system, and you should be good to go. I still add stabilizer to help remove water just in case. DO not add oil to gas, you could screw up the pumps and injectors. There is special fogging fluid meant for fuel though. And yes, the fogging oil burns off pretty quick on summer startup. It makes a bit of a blue cloud lol but that is normal. DISCLAIMER: this is what I do for my engine, others may winterize differently.

 

[Jake 99]

appreciate it vroom. I run ethanol treatment/stabilizer year round, so no issues there. In all the sources I have checked, it's pretty clear that efi 4 strokes should not have fogging fluid sprayed into the intake, so not gonna do that. I was trying to decide between spraying fogging fluid into spark plug holes vs. running some gas + vamaha fogging fluid in a portable tank through the engine. Apparently, yamaha makes a fogging fluid specifically for efi 4 stroke engines. It would be simple enough to disconnect the fuel water separator line and stick the fuel line into a portable gas tank that has the mix in it, then shut down the engine once it starts smoking. I would prefer to do nothing other than lower unit and oil change; however, my service people always fogged it, and they are the best suzuki mechanics in the area.

 

[vroom ZOOM]

If you don't want to spray the intake, that is fine, and pretty pointless as I have said above. Personally I prefer to spray into the cylinders. I have not seen anyone run the fogging fluid through the fuel system in a zuke. I do see the mix method of fogging prevent intake valve rust. I am not sure if it would damage the hp pump and injectors. I know that running that stuff in a mercury optimax outboard will screw it up pretty quick. Check with a zuke dealer before doing that. What the fogging does is it prevents rusting due to condensation from temperature changes. If you are in an area where the temperatures don't really fluctuate, don't worry about fogging at all. As I said, it is meant mostly for two strokes. And really I wouldn't trust any fuel with ethanol for winter storage. I use ethanol free fuel for storage.

 

[vroom ZOOM]

Factory service manual and owners manual do not mention anything about fogging. Seems like the engineers couldn't care less about fogging. Also, get yourself a factory manual if you intend on doing lots of diy work wink wink.

 

[Jake 99]

yep. started off with the service manual and owners manual. That's why I decided to ask what others do since there is nothing in either source about fogging. It's time I called the service people I used to deal with. I'm sure they won't be happy with me not spending hundreds to do this simple stuff, but the fogging question is an important one. What ever they did in the past, one thing is certain - they did not use a lot of fogging mix as it burned off in a few seconds upon startup in spring. My guess is they fogged each cylinder and turned it over a few times. Speaking of which, once I fog each cylinder, will the motor turn with key switch to on if the safety lanyard disconnected? Should I just rotate the flywheel?

 

[vroom ZOOM]

Yep the motor will spin with the starter and the lanyard out... at least mine does. Your service guys do the same proc for all efi 4 strokes regardless of the brand.

 

[Rich672]

Treat the fuel with Starbrite.Pull the plugs, shoot some fogging oil in and turn the flywheel by hand to coat the cylinder walls.

 

[vroom ZOOM]

my DF200 manual says to fog it through the air intake

 

[QBhoy]

I would definitely avoid fogging by way of spraying fogging oil into the intake, on a modern engine like this. Never a good idea. Can play havoc with sensors. I run a mix of 2 stroke through the engine before storage. Do this on my MPi V8 inboard and 2016 mercury 115 outboard too.