Please consult your owner's manual, or http://www.mercurymarine.com for the BEST recommendations on each of these items!
This list will be updated as additional information is requested- check it regularly for the most current information!
Oil:
-These are the "top recommendations".
Refer to your owner's manual for other oil specifications!
-ALL EFI/CARB 2.4/2.5/3.0L (2-stroke) Engines: Mercury or Quicksilver Premium
PLUS
-All STANDARD Optimax (75-250): Mercury or Quicksilver DFI/Optimax Oil
-ALL ProXS Models:
Optimax/DFI Oil. Mercury or Quicksilver Premium
PLUS is acceptable, but Optimax/DFI oil is RECOMMENDED due to a better additive package to help combat carbon deposits.
-ALL Racing/XS Models: Mercury Racing 2 Cycle Oil pn. 92-8M0078011, Mercury Racing Gear Lube pn. 92-8M0078015. Premium Plus oil may be used as alternative ENGINE oil.
- (Note..... there was some conflicting information on Merc's Website- follow this recommendation for the latest information as it's released!)
NOTE: Mercury/Quicksilver Optimax/DFI oil, and Mercury/Quicksilver Premium PLUS are totally compatible with each other. Although you should use the CORRECT oil, you can switch to the recommended Optimax/DFI oil, simply by adding the correct oil to the tank.
NEVER MIX MERCURY RACING OIL WITH OTHER OILS IN THE REMOTE TANK!!!!
Battery:
-MINIMUM 950 CCA for a Fishing Application (the engine ALONE requires 800 CCA). Use Stainless Steel Lock nuts (don't use wing-nuts).
-IF you have a lot of accessories you are running, KEEP IN MIND that this specification is for the ENGINE CRANKING BATTERY. You will need to INCREASE the battery specification to provide adequate cranking capacity based on your accessories being run!
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BATTERY RECOMMENDATIONS:
In a fishing application with today's electronics/pumps/graphs, I strongly recommend a MINIMUM of 950 CCA capacity for the cranking battery.
"BATTERIES THAT MEET THE REQUIREMENT" - Reserve Capacity Monsters!
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Spark Plugs:
-QL77CC (Champion) for 3 Liter EFI's (XB models or 2001 and EARLIER: .035" / All 2002-> Down-draft intake models: .040")
-IZFR5G (NGK)@ .032-.033" for Standard Opti's 135-225HP, 2001 200XS, and 200 ProXS PRIOR TO Serial Number#1B912786
***
-IZFR5J (NGK) @.032-.033 for 75-115 Opti's
-IZFR6J (NGK)for 150/175/200 ProXS (200 ProXS Serial #1B912786-up) & 225-250 ProXS and Racing XS Motors
-2006 & prior ProXS: .032-.033"
-2007 & up: .042-.044" gap for best idle performance. (150/175/225/250 ProXS/XS)
- 2007 & up 225-250 XS/ProXS can use NGK- IZFR6J (gapped to .042-.044") OR IZFR6J-11 (pre-gapped, currently a "factory only" plug)
-2007 & up 225 ProXS: .042-.044" (IZFR6J)
-175 ProXS: .042-.044" (IZFR6J)
*** 200 ProXS Models manufactured PRIOR TO 2/1/12 utilize IZFR5G(NGK) Plugs.
*** 200 ProXS Models manufactured AFTER 2/1/12 (Serial Number 1B912786 and later) will utilize NGK- IZFR6J (gapped at .042-.044") due to production changes in the engines.
-IZFR7M (NGK) for 300XS: .032-.033" (Updated by Don 1/16/2024)
IMPORTANCE OF PROPER SPARK PLUG GAP:
http://www.bbcboards.net/showthread.php?t=5854738/
-All models- MAXIMUM ETHANOL CONTENT: 10%. Ethanol content may adversly affect engine performance.
-See "Mercury's View of Ethanol" on Sherm's board at:
Mercurys take on Ethanol blended fuel
-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.
Fuel/Air Pressures (Optimax):
Two different pressure differentials are used:
-75-115 3 cyl. and ALL XS Racing & 225-250 ProXS Motors (And the 250 Optimax) use 94/109 Air/Fuel Pressures (Fuel pressure equals air pressure + 15psi)
-All other "standard" Opti's use 80/90 Air/Fuel Pressures (Fuel pressure equals air pressure + 10psi)
-IF YOU HAVE NO AIR PRESSURE- YOU HAVE LITTLE OR NO FUEL PRESSURE. The fuel pressure is DIRECTLY relative to the AIR PRESSURE! So- if you have low or no fuel pressure, CHECK the air pressure, and check for AIR LEAKS before you start replacing fuel pumps!
*** Neat little "rule of thumb": If it has "gray" Direct injectors, Air/Fuel is 94/108 and it uses a spark plug that 'ends in J or M' *** (one motor exception- it had black injectors with a "white dot"- consider those to be "gray").
If the direct injectors are Black, Black with a Blue Dot, or Blue, the Air/Fuel is 80/90 and the spark plug probably ends with a "G".
If you find an error in this list, or think something should be added, you can IM me and I'll be glad to update as needed.
Originally Posted by Mckojr
Don, 2014 Mercury 150 Optimax Pro 2 stroke S# 2B117592 -- parts manual shows NGK IZFR6J-11 plugs. I have read where people state the gap is @0.35 isnt it supposed to be 0.41 ish on the 150 Optimax Pro? Dealer replaced my plugs while back and when I pulled them they are all set @0.35. Runs ok but hard to start at times. Low Idle great. Replacing plugs myself this time due to motor hard to start after running. Turns over great but sputters and coughs then fires up but NOW after plug change no difference in starting but idles rough and stalls out on idle. I was able to purchase NGK IZFR6J-11 plugs (pre-gaped at 40ish. -- again when last dealer replaced the plugs they used NGK IZFR6J which they gaped at 35ish. Which plug gap do I use on this motor? Any ideas on why so hard to get running after stopping. acts like flooding with fuel. New batteries, all 3 new fuel pumps, new alternator, new starter relays, fuel pressure in the 90's and air pressure in 100's (sorry gauge doesn't read higher than 100 to give you an accurate number on this)
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