Best gas for Mercury 200 HP Pro XS 4 stroke

[pstone]

Looking for advice and input.    I just bought a 2022 Phoenix 819 Pro with a Mercury 200 HP Pro XS 4 stroke engine.    The manuel says regular 87 octane is fine and the guy I bought it from has had this for about a year or so and that is all he used and it ran fine.     I've spoke with a couple of Marine centers in the area and the consensus is best scenario is use zero ethanol if possible.    Some say it's OK to use regular unleaded (87 or 91 octane) but add an additive from Mercury or Sea foam to treat the ethanol.    I fish year round so the boat won't sit for long periods of time.      Appreciate any opinions/advice on best fuel option for this engine.     

[fishinwrench]

1 hour ago, pstone said:

The manuel says regular 87 octane is fine

There ya go 👍 

Just keep it fresh (less that 3 months old). 

No additives of any kind.  None. 

[pstone]

Thanks, Wrench!

[Champ188]

Phillip, I'm not a mechanic but I'm an old(er) fart with a lot of experience, and I make every effort to avoid ethanol. There's a phone app called PureGas that does a pretty good job of locating places to buy straight gas.

Wrench has far more credentials than me being a sho-nuff marine mechanic. But I can say that I've owned black engines for a big part of my life and I like to think that buying pure gas at reputable stations and running only Mercury DFI (full-synthetic brown) oil in my two-strokes (not a factor for you four-strokers) has helped me get longer engine life and better overall performance.

[pstone]

Thanks, Champ for the input.   I'm actually Perry Stone, not Phillip.    I wish I could fish like Phil!     I decided to run 0 ethanol in this engine after talking with lots of folks including a tech at Mercury.     I can get it at a couple of places in Nixa which is handy for me.    

[Dutch]

When I had a 2 stroke 2002 Opti,  I used 87 octane with ethanol.  My comes by tech said he was seeing fuel line damage and clogged injectors so I had Billy Cooper at Son Sac Marine replace the old ones with the new ones that were supposed to be impervious to ethanol to divert any issues.  I haven’t heard of any issues with ethanol lately.  Personally I use 91 ethanol free gasoline.

[tjm]

I wonder why the manufacturer recommends regular if that is harmful? perhaps because it's not?

I also wonder what other alcohol/ether/solvent they use instead of ethanol to concoct something that meets clean air standards and octane ratings?  

 

[fishinwrench]

2 hours ago, tjm said:

I wonder why the manufacturer recommends regular if that is harmful? perhaps because it's not?

Alcohol resistant materials have been used in outboard and automotive fuel systems since 1999-2002. 

A few random things, like injector O-rings, crankshaft/propshaft seals, some hose, and carburetor gaskets remained until 2006.....but after that EVERYTHING made of rubber-type material was redesigned to be alcohol resistant. 

Nothing made of nylon/rubber/silicone/amphenol/or plastic of any kind will last FOREVER.  But certain technicians will continue to blame "ethanol" everytime anything made of those materials fails.   It's bull----.🙄

Haven't you ever wondered why you never hear automobile technicians cry about ethanol?   It's because they haven't been brainwashed to do so.    The Marine service industry needs to let that ---- go ! 

The only thing I'm aware of that is bad about ethanol blended fuel....is that it has a lower "shelf life".   If you buy it.....then you need to burn it up in a reasonable amount of time. 

And if you believe that "non-ethanol rated fuel" won't turn into horse piss... and eventually shellac....when left to sit for months on end, then either your memory is failing, or you haven't been alive long enough to know better. 

[vernon]

On 9/16/2024 at 1:25 AM, fishinwrench said:

Alcohol resistant materials have been used in outboard and automotive fuel systems since 1999-2002. 

A few random things, like injector O-rings, crankshaft/propshaft seals, some hose, and carburetor gaskets remained until 2006.....but after that EVERYTHING made of rubber-type material was redesigned to be alcohol resistant. 

Nothing made of nylon/rubber/silicone/amphenol/or plastic of any kind will last FOREVER.  But certain technicians will continue to blame "ethanol" everytime anything made of those materials fails.   It's bull----.🙄

Haven't you ever wondered why you never hear automobile technicians cry about ethanol?   It's because they haven't been brainwashed to do so.    The Marine service industry needs to let that ---- go ! 

The only thing I'm aware of that is bad about ethanol blended fuel....is that it has a lower "shelf life".   If you buy it.....then you need to burn it up in a reasonable amount of time. 

And if you believe that "non-ethanol rated fuel" won't turn into horse piss... and eventually shellac....when left to sit for months on end, then either your memory is failing, or you haven't been alive long enough to know better. 

Since end of season is fast approaching, what do you recommend regarding gas that is left in the tank?  I've never been able to figure out how to siphon gas out of a newer model Ranger boat and inevitably there's always gonna be some left to sit throughout the winter months.

I've always added Sta-Bil but after reading your "no additives ever" comment that apparently isn't the answer either.

Thanks.

[Dutch]

I’m not a tech for sure.  All I can do is relate what my small engine guy told me.  I have a snow blower which sometimes goes for a couple of years without being started and a couple of generators.  He said to use Sea Foam in them.  I do and top off with fresh gasoline before I use them.