I have a 2011 Pro XS 225. I have always just ran regular gas with ethanol at any pump, and ran Don’s cocktail with DFI oil. Now we have ethanol free gasoline available locally and I wonder if I would be better off to start running it. Also is there anything I need to do to make the switch? And should I stop additives and just stick with DFI oil when I switch? I sure appreciate all the help!!!
PS. 27:1
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
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IF you are adding oil to the fuel per Don's cocktail be sure you are not adding DFI oil. This has to be a twc3. DFI in oil tank only.Originally Posted by banjerpkr
I shouldve clarified I do not run the oil in the tank. I run quickcare and quickleen.
PS. 27:1
I was just making sure since 4.2 oz. premium plus per 5 gallons of gasoline is part of Don's cocktail for the Optimax. It was not clear to me, I suspect those that matter understood your post.
I'd just stick with the 87 octane 10% ethanol. It's cheaper, and the engine was designed to run it. I ran 100% fuel and I didn't notice and difference one way or the other... Just make sure you add Quickleen and Quickcare... The oil to the fuel is your call... Dan
I will second what Dan said. I would add if your boat sets for a few months during winter I might make the last couple fill ups in the fall 100% gasoline.
I am completely confused about this thread. First, if you can find regular 87 octane non-ethanol gas resonably priced, use it. Stay away from ethanol gas if you have the other option. Second, use quickleen in every tank mixed per instructions on the bottle. Third, use DFI oil in your oil tank not Premium Plus. Do not add any oil to the fuel in your gas tank. Fourth, if your boat since for any length of time, add some Sta-Bil to the gas.
I don’t understand why anyone would add oil to their gas tank. I’ve never done that to any of my Opti engines and don’t know anyone who ever did.
It is to keep your expensive injectors lubricated. In a DFI, no oil is evr mixed with gas. The injectors are left dry. We put Premium Plus (4.25 ounces per 5 gallons) in the tank to keep them little buggers lubricated.
USN Retired
2020 Basscat Caracal
2020 Mercury 225 ProXS 4s
Does Mercury recommend this?
They cannot since it will alter the EPA emissions and would be subject to their wrath. Mercury mechanics do recommend this though. There are plenty of threads on it if you want to read about it.
USN Retired
2020 Basscat Caracal
2020 Mercury 225 ProXS 4s
Alcohol is a double edge sword. It is a very good solvent meaning it will clean some things very well and it has good anti knock qualities. The main problem is that is if to much water gets in the fuel it will cause Phase separation from the gasoline. When allowed to set one place for while it can cause serious problems. In parts of country where the humidity is high most of the time this becomes a serious issue as the fuel tank breathes a lot of moisture in the air condenses to water causing this problem. Where I live in Ca. it is never a issue. It is important to turn your fuel over quickly and only use TOP Tier fuel.
Even with no alcohol in you fuel your tank will absorb the same amount of water as with it. It will not mix with the gas and goes straight to the bottom of the tank, still a problem butt nearly as corrosive as ethanol/water mix.
If given a choice as long as it is top tier I would prefer no alcohol even though I have never in my rigs had any issues with it.
I use only premium plus in my motor I motors stay as carbon free as anyone the uses DFI. I do use quick clean and almost always Chevron fuel with Techron. Something else I should mention is just because they allowed to use 10% does not mean that the do. I test alcohol content in fuel often and I have found that Chevron fuel never exceeds 5% alcohol.
Testing alcohol content is very easy to do and every serious boat owner should do this once and while.
Premium Plus added to your fuel has proven to improve fuel and direct injectors function and alleviate some performance issues.
Last edited by lpugh; 06-23-2018 at 05:32 PM.
Thank You Leon Pugh
I agree, you are confused. I am just kidding, sort of.
Remember, Mercury designed these engines to run on fuel with a maximum ethanol content of 10%. I've got a choice when I head to the lake... I buy 87 octane with 10% ethanol... And buy a couple of bags of plastics with the money I save... As long as you put in what you'll use that day, don't let it sit for extended periods of time and add Don's cocktail you'll be fine... Remember Mercury designs, test and recommends 87 octane with no more that 10% ethanol from high volume retailers... Dan
Actually they recommend a MINIMUM of 87 octane and a maximum ethanol content of 10%.
I have a 1999 225 opti with close to 500 hours and never used dfi oil.
Only prem plus. When the pro xs first came out mercury told us techs
not to use dfi oil.
I used to be indecisive. Now, I’m not so sure!
Thanks for the info. My engine is a 2007 Pro XS with around 400 hrs on it. I have never added PP oil to the gas. Would I still benefit from this or are my injectors past the point of no return on benefitting from the 4.25 oz per 5 gal mix?
See the FAQ - Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations
You replace one injector (I had to) and you'll understand the recommendation to add Premium Plus to your fuel. I had Don service/clean/validate my complete fuel system, and before I ran it, I added PP to the full tank of fuel at the recommended ratio.FUEL:
-All models- MAXIMUM ETHANOL CONTENT: 10%. Ethanol content may adversly affect engine performance.
-See "Mercury's View of Ethanol" on Sherm's board at: http://www.bbcboards.net/mercury-mot...nded-fuel.html
-Standard Opti's (ALL) 87 Octane MINIMUM.
-Standard 2-stroke Carb/EFI Models: 87 Octane MINIMUM.
-XS, XB or Racing PRIOR to 2006- CONSULT OWNER'S MANUAL! Most require High-Test!
-ProXS and 250XS 2006-UP: 87 Octane MINIMUM. IF poor idle quality occurs, could can try 89 Octane (mid-grade) to see if quality improves.
-300XS- Consult Owner's Manual. High Grade (minimum 91 Octane) fuel required!
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 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).
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"Mercury Component Cocktail"- for EVERY tank of fuel, whether or not your fuel contains Ethanol: (Chemically, this works much the same as the previously recommended (and now to avoid alcohol content) cocktail, and requires less components.) This is Don's Preferred "Cocktail":
-1oz Mercury QuickCare +
-1oz Mercury QuickLeen
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Per 5 Gallons of Fuel (in EVERY TANK).
In addition to the above, it is acceptable to add 150:1 mix of Premium PLUS in the fuel tank (for OPTIMAX engine models). This has been proven to benefit fuel system components by providing additional lubrication ONLY to the fuel system components (especially the direct injectors- which are often left DRY after engine shutdown).
(If leaving fuel in boat for more than 30 days, be sure to also add Mercury QuickStor).
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Fuel Selection:
Make your fuel selections based on the following criteria, IN THE FOLLOWING ORDER:
-High Traffic, Top-Tier (Name Brand) Fuel
-Appropriate Octane Rating (see above info)
-Lowest possible ethanol content (NEVER to exceed 10%).
-While it may be preferable to utilize a fuel that contains lower (or no) ethanol, use of fuels that are SUBSTANTIALLY higher octane can result in decreased performance, decreased fuel economy, and potential for carbon buildup. Higher octane fuels burn SLOWER and COOLER.
These concerns have been beat to death on the forums. Read Don's recommendations in the FAQ topic and choose to follow his recommendations or ignore them.
I use top-tier ethanol fuel at the recommended octane level and always will.
_______
Phil
'09 Hewescraft ProV
'09 150 Optimax
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Corn is for corn flakes not motor fuel. If you can avoid ethanol you should. Talk to any injector service guy that knows about optimax fuel injectors and he will tell you you are a fool if you don’t add oil to your fuel.
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