To fog or not to fog?

[stcriox]

First year winterizing my 08 Yamaha 150 four-stroke. Yes, the manual says to fog the motor through the air silencer. However, I have heard and read (on this site) two things:

First, you should NEVER fog an EFI outboard. This because of damaging the sensors. True or False?

Second, you should only fog through the carbs, then turn the engine over (lanyard off) to disperse the fogging oil.

Can I assume that I should rely on my manaul? Or, should I not fog an EFI motor through the air intake?

My confusion lies in the fact that my manual for my old motor (05 Mercury four-stroke) said only to add a small amount of oil in the carbs.

Thanks in advance for the advice.

[ebijack]

if you do a search (here on WC)you'll get alot of info. still to this day there are alot of supporters on weather to fog or not, and how to fog. alot does depend on where you live, how long your storing your motor. and the temperature range it will be stored in. i fog the cyl's thru the spk plug holes (both 2 and 4 stroke) then turn the motors over by hand to distribute the stick fogging oil to the cyl walls. i never fog my lawn mower or weed wacker and those motors get the worse abuse. personnal beliefs/experience are my excuse. i've been working on/with motors for 41 yrs. that's how i got so opinionated in my belief :)
just a note: procedures are written to cover everywhere the motors are sold.. from brazil to alaska and were developed to cover every condition that could be encountered. that's one reason there are soooo many who have experiences with what/why/how they do what they do. but like mentioned below, if you have a warrenty then have the dealer do it ( if you trust them). carburated motors, EFI and DFI all have a different requirement as to what they need done. and how it's done.

[Hot Runr Guy]

You've got a $10K investment on the back of your boat. If you're not going to have a dealer perform the winterization (thus providing you a receipt that it was done), I would certainly follow the manual to the letter. I'd go so far as to purchase the exact Yamaha fogging spray, again, just to have a dated reciept.
HRG

[Modog]

HRG nailed it. Keep all dated reciepts, at least until your warranty period expires.
Those records might be appreciated by a prospect buyer when you're ready to sell too.

[jtourangeau]

Mine is a 2000 efi,after fogging the intake I take out the plugs and fog the cy.walls.No prob. to date.If it were a 08 or any warr.left I would at least call and talk to my yam. mechanic,the same place I would take for warr.work.

[stcriox]

Thank you for the responses. I spoke today with the Yamaha mechanic at my dealership. He told me that when they fog Yamaha four-strokes they only remove the plugs, spray fogging oil for about 3-4 seconds, and then turn the motor over (with lanyard off) several times to displace the fogging oil.

I think I will still spray fogging oil into the air intake, as per the manual. Also, I will remove the plugs and spray, then turn motor over.

I have kept all of my receipts for the fogging oil, lower-unit gaskets, oil plug gasket, lower-unit fluid and four-stroke oil. Thanks for the advice on that matter. I have always winterized my motors, so I thought I would do the same with this one.

On that note, I have used Amsoil four-stroke outboard oil (10W-30) on my two previous four-stroke outboards. The guy who winterizes the DNR boats in my state suggested Amsoil. What are your thoughts on Amsoil vs. Mercury, Yamaha, Suzuki oils. I know, I have opened a can of worms with this question.

[SteveJ]

On that note, I have used Amsoil four-stroke outboard oil (10W-30) on my two previous four-stroke outboards. The guy who winterizes the DNR boats in my state suggested Amsoil. What are your thoughts on Amsoil vs. Mercury, Yamaha, Suzuki oils. I know, I have opened a can of worms with this question.

You have opend a can of worms with the Amsoil question. Generally speaking, those that have not used it hate it and those that have used it think it is the best. I have used it for years and wouldn't think of using anything else.

[guest]

If you use amsoil and your engine blows up it will not matter if by using amsoil was the cause the manufacture will blame it on the amsoil and you for not using recommended products by manufacture

[Dillon]

Amsoil Marine 4stroke oil is a recommended product for Yamaha 4stroke outboards. Its use absolutely will not void a warranty. I have run Amsoil products in all my internal combustion engines for over 20 years with outstanding results. I do not sell Amsoil and am not affilliated with anyone that does, they are simply great products.

[stinkycat]

I am in the same situation but I figure I will fog like the manual says. My manual says the exact same thing as the 150 and mine is a 75 4st efi.

My problem is I do not know what the "air silencer" is. And my manual does not show any diagrams to point out what it is.

Can anybody point me in the right direction?

Thanks for any help!

[Hot Runr Guy]

I am in the same situation but I figure I will fog like the manual says. My manual says the exact same thing as the 150 and mine is a 75 4st efi.

My problem is I do not know what the "air silencer" is. And my manual does not show any diagrams to point out what it is.

Can anybody point me in the right direction?

Thanks for any help!

Stinky,
Here is the diagram from the online Yamaha parts site, the intake silencer is on the left, item #13.
HRG

[MarkG]

4 Strokes really don't need to be "fogged" ,,which the true definition of "fogging " is spraying storage oil into the intake while the engine is running to coat all the moving parts with oil. A 2 stroke required it because,by nature , it is the only way to get oil to all the parts,both on the top and bottom end,(crankshaft,bearings,etc) . Just spraying oil into the cylinders is not "fogging". The term gets thrown around incorrectly, this is why people get confused.

4 strokes do not need "fogging" because pretty much all the moving parts are already coated with crankcase oil. In fact,fogging a 4 stroke does not even reach or have any effect on 99% of the moving parts in a 4 stroke. All it does is coat the intake passages (which may even be a bad idea for an EFI motor) and get a bit of oil into the combustion chambers and valves. You can do that by pulling the plugs and spraying oil into cylinders. But this is not really "fogging".

[stinkycat]

Thanks for the Info HRG and others!

[1shooter]

so what are you going to do?

[stinkycat]

I plan on fogging through the spark plug only. I figure that won't screw up any sensors on the way to the cylinder.

[I Walleye]

I have always fogged my outboards but never fog the more abused stuff either. Chainsaws, weed wackers, snow blowers, leaf blowers etc and they all start just fine. The biggest problem I have with fogging the outboard is waking the thing up in the spring. It takes alot to burn all the junk out after its sat for a winter.

[REW]

Stcroix,
A 4 strok engine is a 4 stroke engine is a 4 stroke engine.

If an oil is rated to adequately lubricate a 4 stroke engine, - whether it is use in an auto, an airplane, or boat - it will lubricate the engine correctly.

Pay your money, take your choices and enjoy your purchase.

Take care
REW

[Merc175]

I wouldn't fog thru the air intake on an EFI motor of any kind. My Merc motor specifically says not to fog thru the intake because it can harm the injectors, primarily.

All you have to do is spray oil into the cylinders by taking out the spark plug, and cranking the engine over after oil was applied.

Fogging a 4 stroke motor is not really necessary, IMO. Much different than a 2 stroke..