[Fish Hawk]

Some people consider Sea Foam more of a "cleaner" whereas Sta-Bill is more of a fuel "conditioner".  Certainly not saying one is a better product than the other - each just has their purpose.  And that's an ongoing debate you'll find on other sites like bassboatentral & crappie.com

For me, marine Sta-Bill at every fill up.

+1
Sta-Bill all the time and Sea Foam every now an than

[craigm]

 from a message from Don in a thread on 4/24/12 Don is th3 mercury outboard guru from BBCif he sadi it merc recommends it . he also stated it is perfectly suitable for all merc 4 strokes check it out BBC.com

Fuel Additive Recommendations:
-Stabilize fuel ANYTIME fuel will not be consumed and replaced within 15 days!!!
 -Optis (ALL, including XS & ProXS): Quickleen in EVERY TANK OF FUEL. You CAN combine Mercury QuickCare or QuickStor Fuel System Treatment & Stabilizer (or Sea-Foam if you prefer it) with Quickleen. Use the recommended "dose" of each product per the bottle instructions. For anyone questioning Quickleen recommendation- see Service Bulletin 2001-12 (yes, it's been recommended since 2001!!!).
 -Quickleen may be used in ANY Mercury engine- it helps to prevent/remove carbon buildup (primary purpose).

 ------------------------------------------------------------------------------------------
"Mercury Component Cocktail" (Chemically, this works much the same as the below mentioned cocktail, and requires less components.) This is Don's Preferred "Cocktail":

 -1oz Mercury QuickCare per 5 gallons fuel
 -1oz Mercury QuickLeen per 5 gallons fuel
 (If leaving fuel in boat for more than 30 days, be sure to also add Mercury QuickStor).
 ------------------------------------------------------------------------------------------

"Alternate Cocktail" (IMO, this combination results in clean injectors, direct injectors and spark plugs):

 -1oz Marine Stabil or Mercury QuickCare per 6 gallons fuel
 -1oz Quickleen per 6 gallons fuel
 -1-2oz SeaFoam per 6 gallons fuel

[Fishless]

I have the 4 stroke 60hp mercury which is under the 5 and drive warranty from mercury ( 5 year coverage) soooooooo I only use mercury products whether cleaner or sta-bil type products figuring if there is ever a problem under warranty I don't want an excuse for non coverage of warranty

sta-bil type products are for fuel conditioning especially with our high alcohol content fuel, as Brent at performance marine (mercury) shop told me with the alcohol fuel if your boat is going to sit any length of time you either want your fuel tank completely full or completely empty so you don't get water condensation in your fuel tank

[wadefisherman]

I've never used any additives in my 4 stroke yami 150, take it in for routine maintance annually = no worries on the water for past 6 years. Oh and go to the lake regularly to keep the fuel fresh.

[menrats]

jeez i missed this memo. i only thought these products were necessay for a bad running engine or after six months plus storage. thx guys ill throw a little sea foam in next fill up. 1oz to 6 gallons? i still struggle to spend 32 bucks for evinrude oil when i can get tcw3 at walmart for 12? wtheck do i know.

[OneBlade]

jeez i missed this memo. i only thought these products were necessay for a bad running engine or after six months plus storage. thx guys ill throw a little sea foam in next fill up. 1oz to 6 gallons?

Quotes above say 1oz per 5-6 gallons.  But I also thought I've read 1oz per gallon.  Perhaps the later is for cleaning and the former is for maintaining.  I'll probably follow cousinlll and FishHawk combined approach -- use Stabill all the time on ratio the instructions give.  Once a year or something I'll use 1oz per gallon of Seafoam to clean it out - most likely in the warm season when my motor starts and runs its best.

[Papermouth]

This was a good read, thank you all for sharing the info.