4 Stroke Fuel Additive

Will be getting in my first 4 Stroke. It's a mercury. I won't use Stabil but wondering what you guys are running in yours.

Straight up 10% ethanol, oh the horror.

Just use Mercury's Quickleen and Quickcare with every fill-up... Dan

Stabil

If you consistently burn through a tank every several weeks, use as much as you do in your car.

Yamalube Ring Free Plus...every fill up...

No reason to throw money away on snake oil that does nothing

New 4 strokes are designed for 10% ethanol. No need to put anything in it unless you are storing it for a long period.

I run non-ethanol in my 2021 4-stroke Merc, but I will add the (2) Mercury products periodically.

Stabil, can't go wrong with it

I use star brite marine because it’s inexpensive and locally available.

The whole fishing industry is snake oil 🤣

Yes, but something's actually serve a purpose. Ethanol treatments serve no purpose and don't do anything

Read an article on this several years back, concerning cars. "Independent survey". Techron was the best for 4-strokes. Personally, I run Sea Foam. I have used this for probably 25 years and never had an issue. Just my 2 cents

Sea Foam during the winter....nothing during the summer. Burn gas way too quickly to think about additives.

You don’t need anything in it honestly.

Just use ethonal free gas or Super Unleaded if it’s not available.

My Yamaha 4-stroke calls for 10% or less ethanol 87 octane fuel. It’s been getting just that and only that for 19 years. Still runs really strong, smoke free, and quiet.

If it requires something else, the owners manual didn’t include it in the list.

One can of Seafoam each fill up...done... it does what it claims period, proof, all my outboards over the years 2 strokes, and now my new 4 stroke you can take your finger and swipe the inside of the exhaust hub on my prop and no soot, look at those who don’t run it and you will have black soot on your finger... when I traded my 2014 250 ProXS in on this 4 stroke the mechanic was doing compression checks on the cylinders and was shocked to find the factory spark plugs still in the motor, and clean as a whistle!, I would pull them check the gap and inspect the ceramic and index them back - plugs today being iridium won’t wear out and last a long long time... I told him seafoam every fill up was why, he smiled... same goes for my Harley, I run seafoam all the time, pull the plugs, plugs are clean, put a light into the cylinder and the tops of the pistons look great... Seafoam works ! ( not a paid representative)

YUP YUP YUP!!

The recommended spark plug replacement schedule is overkill

Amsoil Quikshot for me

Sea foam marine , good stuff

another seafoam fan, been using it for about 15 yrs. and the stuff works.

my tank is 32 gal. and I put one of the big cans in every other fill up (normally 10-15 gal) and once a yr. I will put 2 of them in to clean any possible carbon build up.
95 200 xir efi mercury runs like a top.

Amine/nitrogen detergent additives like Techron for four strokes

Seafoam for two strokes.

I like this post thread. I’m a big fan of Sea Foam but haven’t used it in my boat gas. I’m a Yamaha outboard fan and I’ve used ring free for a longtime with great success. I bought a new bug last year with the SHO and my dealer recommended ring free for it. I only have 7 hours on it so all good of course. I sold my 2007 Ranger with the 225 HDPI and never had a problem. The motor had ~250 hours on it when I sold it. So all advice sounds good to me.

If I’m not mistaken, SeaFoam does nothing for condensation and /or water in gas or phase separating. It’s awesome for carbon and cleaning engine parts. I could be wrong on this.

it is a stabilizer just like sta bil. half the reason I use it with other half being the clean factor. as for condensation, I have never had any water in gas problems since using it is all I know but I also run some heet twice or 3 times a yr. to get any out.

Hoppiiiieeeeeee!!!! thanks bud

Nothing

Why not use Stabil?

What is the advantage of using 93 octane gas?

No advantage to use 93 in a motor that is designed for 87.

Or 87.

Fixed it, totally fat fingered the 8 with a 9

i spoke to Merc about this... he said yes the motor will run on 87, that is the min, but it will run better on 91+, i then asked if racing fuel would be better he said no, keep it 91, 93 or 94 if available in your area so the computer is not compensating for knock with the low octane and robbing power, he said the computer also learns your habits and throttle usage for the "eco" feature, so he said to run it hard frequently to keep it suppling more fuel for WOT, because if your normally a conservative driver it will hold back on letting go of the juice and rob you of some power...

I run Seafoam but just started using it, I also put some Stabil in it as well. Has anyone ever tried Marvel Mystery Oil in there 4 stroke outboard? I keep a bottle of it and give everything around my place; but my boat, a dose of it. My dad swore by it.