Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations Updated 1/16/2024

[Scott AU]

Hay Don,

I have a 2011 Mercury Optimax Pro XS 150 (Ser. No. RGR03082B111A). I am replacing the plug with the oringinal IZFR6J, but wasnt sure what the gap needs to be. The owner manuals says .030, but I see where you have 2007 & up: .042-.044" gap for best idle performance. (150/175/225/250 ProXS/XS).

What should I use. I am assuming the owner manual is the correct one, my buddy bought the boat used.

Thanks,

Scott

[EuropeanAM]

Hay Don,

I have a 2011 Mercury Optimax Pro XS 150 (Ser. No. RGR03082B111A). I am replacing the plug with the oringinal IZFR6J, but wasnt sure what the gap needs to be. The owner manuals says .030, but I see where you have 2007 & up: .042-.044" gap for best idle performance. (150/175/225/250 ProXS/XS).

What should I use. I am assuming the owner manual is the correct one, my buddy bought the boat used.

Thanks,

Scott

Manual may, or may not be correct.

If you would, please provide your engine's serial number (what you provided was the hull ID# for your boat).

[Air&Sea]

Hi Don, a few question please:

On a 2007 250 Pro xs Serial # 1B548243

Which is the best fuel to use: 87 with ethanol, 89 with ethanol, or Rec 90 no ethanol? Is it better to go with the higher octane to get away from the ethanol or use the correct octane fuel with less than 10% ethanol and the cocktail of additives?

Is it ever recommended to increase the amount of Quickleen you put in the fuel to shock treat or de-carbon the engine?

I had to replace two ignition coils which have a new part number. Old coil 879984A-1 / new coil 8M0077471 Is there any difference? Is it best to replace all the coils to the new part number?

Please confirm the correct spark plug is IZFR6J and the correct gap is .042 to .044.

I have been reading all of your posts, THANK YOU for being so helpful!

[EuropeanAM]

Hi Don, a few question please:

On a 2007 250 Pro xs Serial # 1B548243

Which is the best fuel to use: 87 with ethanol, 89 with ethanol, or Rec 90 no ethanol? Is it better to go with the higher octane to get away from the ethanol or use the correct octane fuel with less than 10% ethanol and the cocktail of additives?

The following excerpt is from the FIRST POST in this thread, and answers this question:

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.

Is it ever recommended to increase the amount of Quickleen you put in the fuel to shock treat or de-carbon the engine?

IF required due to carbon buildup, a double-dose of Quickleen can be safely used. This is normally NOT necessary if running the correct fuel, correct oil, and the engine is running properly.

I had to replace two ignition coils which have a new part number. Old coil 879984A-1 / new coil 8M0077471 Is there any difference? Is it best to replace all the coils to the new part number

Per Service Bulletin 2009-026, it is recommended that ALL ignition coils be replaced, if an ignition coil failure has occurred.

Please confirm the correct spark plug is IZFR6J and the correct gap is .042 to .044

As stated in the very first post in this thread, IZFR6J, gapped at .042-.044" is correct.

[Scott AU]

Don, the correct serial no for the 2011 Mercury Optimax Pro XS 150 is 1B841288.

[EuropeanAM]

Don, the correct serial no for the 2011 Mercury Optimax Pro XS 150 is 1B841288.

IZFR6J, gapped at .043-.044"

[Scott AU]

Thanks,

Thats what I thought but wanted to make sure.
Not sure if he has the correct manual that had the plug gap listed at 0.030

[EuropeanAM]

Thanks,

Thats what I thought but wanted to make sure.
Not sure if he has the correct manual that had the plug gap listed at 0.030

He may have the correct manual... plugs and/or gaps that are updated are usually done so via Service Bulletin, or notification in Technician Course Material.

[michael2277nh]

Don, as someone who is new to owning a boat, 2004 triton tr20X Bass master classic edition, I have blown 2 different powerheads on 2 different motors in less than 6 months last year. I never pushed my motors to more than 66 MPH and always treated with the proper gas, quickleen and Merc Oil. Thankfully the motor I bought from a friend was still under warranty. I know it was very unlucky, but I have to say that I really appreciate all your input on all the replies. I don't think it would have helped avoid my issues, but at least I feel that if I need any advice or info, you are certainly someone I would ask first. I am sure many of us on this site really appreciate all your help and info. I just thought you should know as I know others have stated too. Hopefully I will have a luckier year this year with my motor.

With that being said, my powerhead was replaced last october. I was able to run it for about 3 or so hours at interval RPM's before winterizing. Do you have any suggestions on what I should do when I take it out for the first time in the next month or so? Should I start mixing in the proper quicksilver oil into my fuel along with the quickleen? Any info would be greatly appreciated as I hope that I can get through this year without any engine problems... lol

Thanks in advance!
Michael

[EuropeanAM]

Michael:

I would follow the recommendations made in Post #1 of this thread.

If you wish to add 150:1 Premium Plus to your fuel, that is certainly a good idea (note- this is not used as an "engine lubricant"- it is simply lubricating fuel system and injectors/Direct Injectors).

Also, verify proper winterization/maintenance have been done (everything UP TO DATE), and complete the break-in on the engine:

http://www.bbcboards.net/mercury-3-l...x-engines.html

http://www.bbcboards.net/mercury-3-l...endations.html

[MickeyBlue]

would this work for carbed motors also? just had some problems with water in the lower carbs. caught it before it damaged anything. looking for something to prevent that from happening again. changed separator and fuel lines today.

[Savage]

would this work for carbed motors also? just had some problems with water in the lower carbs. caught it before it damaged anything. looking for something to prevent that from happening again. changed separator and fuel lines today.

No,oil is being mixed with the fuel already

[EuropeanAM]

Correct- the 150:1 premix option is for OPTIMAX ENGINES ONLY.

[MickeyBlue]

should've asked different. I meant the cocktail for the fuel. is it just for injectors? ive got a 225 promax with carbs on it. found out the bottom carbs had broke down fuel line in the jets. would only plane if I held the choke in. thought it had gummed up so was curious of a fuel additive mix that would help with carbs.

[SilverFox579]

The cocktail (Quickleen/Quickcare) is for all engines but the addition of Premium Plus to the fuel at 150:1 is exclusively for Optimax engines. No additive will prevent fuel line degradation, see this for what you need to do - http://www.bbcboards.net/mercury-3-l...ulb-first.html

[MickeyBlue]

thanks for the info. I just replaced the fuel lines and put in a new water separator and an inline filter when I had the carbs rebuilt.

[Preach the Word]

I see there are Gel batteries recommended. Does the alternator produce too much voltage for the Gel? I had read that subjecting a gel battery to more than 13.8 volts for an entered time would be ruinous to it.

[Savage]

I see there are Gel batteries recommended. D oes the alternator produce too much voltage for the Gel? I had read that subjecting a gel battery to more than 13.8 volts for an entered time would be ruinous to it.

No.

[EuropeanAM]

I see there are Gel batteries recommended. Does the alternator produce too much voltage for the Gel? I had read that subjecting a gel battery to more than 13.8 volts for an entered time would be ruinous to it.

Absolutely no problem, as long as it's a PROPERLY RATED battery, and fully-charged each time you head out for an outing.

[Mtbrtw]

Where is my fuel filter loated on my 97 EFI 200?