2013 Mercury 200 Pro XS spartplug fouled & alarm

[Godude]

2013 Mercury Pro XS
Serial #1B975402

Engine cut out on speed recently, so I pulled the plugs to check them all and found one was fouled out. Replaced the plug. Just went back out on the water and engine wouldn’t plane off. Pulled the cover and stupid me left 2 of the plug wires off. Put them back on, took off and motor ran great very briefly, then cut out again. Boat normally runs 68-70, but would only do 60. Then I started getting a single, long beep alarm each time . Oil tank is full of oil, so I knew I was ok on oil. Put it back on the trailer, pulled all the plugs and they looked ok, but the single alarm is puzzling me because the only time it has gone off is when I’m low on oil. I typically do all my repairs, so any help would be appreciated.

[Godude]

Update; took the boat back out after checking the plugs again. No alarms initially and ran wide open. Turned around to come back and it would only run about 60. Idled through a no wake (alarm sounded; 1 long beep), hit the throttle again and then it only got up to 52. Made my turn to come back and it ran wide open again. Acts like sparkplugs are going in and out, but it’s never done this before. Maybe I should go ahead and change all of them??? It’s been less than a year, but you never know. Any other troubleshooting ideas out there?

[lpugh]

INspect coils carefully, perform a coil outout KV test.
It would be in your best intrest to have the computer scaned and request a printout, there should faults stored to lead in the the right direction
While at it Air/fuel presures tests as well

[Godude]

Thanks Leon. I talked with a buddy of mine, he mentioned the coils also and said it would have to be tested too to figure out which one.

[Godude]

Update; Did a sparkplug, coil and injector test. Everything checks out unless I’ve got a coil(s) going in and out while on the water. Is this typical behavior before a coil goes out completely? I guess pressure tests would be next step?

[Godude]

Anyone had any success using the quikclean products for cleaning injectors? I’ve heard sparkplug changes will be a must after this is done due to all the carbon flushing through the system.

[lpugh]

It is really not for cleaning, it is for maintenance and should be ran with every tank of fuel. If the injectors are bad enough to have a performance issue they should be sent to European Marine for proper service and validating
Quickleen will not cause the plugs to foul out, you bad info on that one
Describe how you tested the coils and exactly what were the results, KV output (how wide of a gap will the spark bridge)do they all have the about same output voltage. What were the ohm test measurments

[SilverFox579]

I believe you may be thinking of some other Mercury product, possibly Power Tune, as Quickleen is a specific fuel treatment strongly recommended to be used in every tank of fuel, see this topic in the FAQ at top of 3L forum - Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations

Visually inspect each coil for any evidence of a foam looking material oozing from the coil. If no visible clues, a spark and cylinder drop test are probably in order.

Btw, your 200 is a 3L and is covered here - Mercury - 3 Liter & 3 Liter High Performance

[Godude]

Leon, I was specifically talking about Quikleen #2, engine and fuel system cleaner, not Quickcare #1 which is for every tank of gas. Should I be using 1,2 & 3 with every tank?

Phil,

I tested the plugs using a sparkplug tester. I tested the coils and injectors by unplugging the electric plug to the injector and listening for the change in the sound of the engine. I realize that this is not a visual inspection of the coils and injectors, but a start to try to troubleshoot my issue.

Bought a full set of plugs today. Also bought an impeller (what the heck, hasn’t been changed 3 1/2 years) and ordered thermostats. All maintenance items that needed to be done and I’m thinking the thermostat(s) could be a possibility for the issue. Thoughts anyone on the T-stats? Could or will the Gardian system reduce power in the engine due to detecting a bad t-stat?

[SilverFox579]

Leon, I was specifically talking about Quikleen #2, engine and fuel system cleaner, not Quickcare #1 which is for every tank of gas. Should I be using 1,2 & 3 with every tank?

No. Quickare plus Quickleen in every tank. If you read the topic I linked earlier, you'll also find a recommendation for adding Premium Plus to your fuel to protect your injectors. This is commonly referred to as the "cocktail".

Based on your other comments might also review the annual maintenance topic in the FAQ, spark plugs and water pump service are annual recommendations. If your plugs are as old as your water pump, I'd replace the plugs and service water pump then see how the engine runs.

[Godude]

Thanks for the reply Phil. The spark plugs were changed within a year ago. I run non-E gas when I’m able to find it and always run at least Premium Plus whenever I can’t find non-E. I also add either Quickcare or Bell Performance Marine MXO (my preference) every fill up. This is first time I’ve heard of also using Quickleen with every fill up. Thanks for the advise. I’ll be putting the new water pump impeller on today (had to get new gaskets). The old impeller still looked good, but replacing it anyway. New plugs will also go back in today, along with the new thermostats. Fingers crossed that one of these will resolve my issue. Feel good about doing them all though. Any tips or tricks with regard to replacing the t-stats? Thanks.

[SilverFox579]

Can't offer any advice on the stats, 2.5L Optimax (what I have) are different than 3L, but I'm sure there's info about them in the 3L forum.

Be sure to check out the FAQ, there's a ton of great information in it, here's just one - Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations

Just the fuel recommendations from the linked topic...

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).

------------------------------------------------------------------------------------------
"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
----------------------------
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).
------------------------------------------------------------------------------------------
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.

[Rip Bass]

Godude, you should be running 87 octane in that engine,even if it has 10% ethanol. In my experience,Opti’s do not like higher octane fuel,even 89 will cause excess carbon build up and plug fouling and 90+ is worse.

[EuropeanAM]

+1

BTW... moving this thread to the 3L Forum (correct location).

[Godude]

Well, after replacing the impeller, thermostats, testing the plugs and coils, then replacing the plugs, I finally have an engine running good again with no alarm going off (as I keep my fingers crossed). Thanks to everyone for their input and tips. These were all items that needed to be done, but more than likely it was probably a bad spark plug even though they tested out ok. Since having this boat, spark plugs have been an ongoing maintenance issue. They just don’t last as long as I feel they should and I always find myself doubting that it could be plugs again. Oh well, I guess new plugs once a year is not a bad maintenance investment if it keeps the Merc purring.

[Godude]

Thanks Don. I could have sworn that I chose the 3L forum originally, it guess not. Sorry about that. BTW, the oil pump that I bought from you is still doing the job. Thanks.

[EuropeanAM]