Pismo10

I am still looking for the final word on fogging EFI engines. I have a 1996 Gen VI 502 Mag with a VST. The merc owners manual that came with the engine says to pour 1oz of 2 stroke oil into the VST then run it out if gas by turning off the fuel supply at the tank. I have been doing this but it seems to do little, the engine runs a long time until it dies, there is no, not even a little, smoke out the exhaust like I used to get fogging old carb motors(so I knew the fogging process was working). Maybe it is doing enough, I just dont feel good about it. I have also read that there was a merc bulletin say not to fog EFIs because all it does is clog up the injectors. Others say to fill the water seperator half way with 2 stroke oil and then run it out (this is a pain, gas and oil spill, etc) Others say put the oil in the VST, remove the water seperator and run it out which now does not take long. Any final thoughts appreciated. Thanks

Dave M

I don't fog mine. After several years I've never had any issues. My boat is only winterized for 3-4 months. If it was for long term storage, I might reconsider.

tahoetech

I run omc 2+4 fuel conditioner throught the fuel systems. I run the boats for about 20 minutes so I can also change the oil easier. I then use fogging oil in an aresol can. I fog very slowly until the can is about half way gone(with the engine at about 1500) I then rev the motor about 5 or 6 times to get most of the fogging oil out of the intake manifold.
Merc and volvo both say to use a mixture of two stroke oil/ fuel conditoner/ fogging oil/ and gas in a remote tank. I have found that the injectors seem to clog up alot. Most of the (vst) fuel resevoirs with floats are coked with that crap too. They also say that the intake has a "special coating" on the aluminum and to not get it oil soaked. ?? Ive had alot of intakes off and they all look like regular old aluminum to me.
If you do this right there will be very little fogging oil left in the intake manifold. The rest will be burned off when started next.

Pismo10

Here is the latest from merc. I think I could decrease this recipe by several fold and not have so much leftover.

http://www.boatfix.com/merc/Bullet/01/01_15.pdf