Plug wire secrets? 2019 250LPXS 4.6l V8 4S

[knopf]

Hi,

I have a 2019 250 Pro XS V8 4S. Model 12500033A, Serial 2B644524.

Almost at 3 year mark. The motor has around 80 hours. On Thursday after about 2 months of garage duty, it started missing on first run to spot. I read on here about some issues and decided to check the plugs. It looks as if two of the plugs may have fouled. I bought plugs and have replaced them. How in the world do you get the wires to "snap" back on the plugs. I am not a mechanic but have been in the automotive repair industry over 40 years. These are being a pain in the butt. Anyone have any secrets?

Thanks in advance.

Scott

[Pulsare2020]

Good question. I changed my plugs around 50 hours and about 3 of them would not "click" no matter what I did when I put them back on. Perhaps they were that way from the factory, perhaps it was other issues. I had other issues that Don corrected under warranty and he did replace all the plug wires as well, and I have not removed them since.

[knopf]

I am going to answer my own question for those who have viewed my post. Mercury has an issue with the plug wires. Initially Mercury was blaming people when they removed the wires from the plugs. But now there have been two revisions to the plug wires. I am told the first gen wires (have a decal around the wire) were junk. They may be the root cause of the plugs fouling. Also, the metal contact in the wire back slide back when you push the wires on. If anyone is having issues this is a warranty condition.

Scott

[thommo59]

Would be interesting to see a pic of all 3 types side by side so we could easily identify them. I have just over 90 hours now and replaced plugs and leads at my cost and recently have developed a miss that comes and goes. Do you have any further details on how to identify these?

[EuropeanAM]

I am going to answer my own question for those who have viewed my post. Mercury has an issue with the plug wires. Initially Mercury was blaming people when they removed the wires from the plugs. But now there have been two revisions to the plug wires. I am told the first gen wires (have a decal around the wire) were junk. They may be the root cause of the plugs fouling. Also, the metal contact in the wire back slide back when you push the wires on. If anyone is having issues this is a warranty condition.

Scott

Partially true- Partially false.

Most of the problems did stem from over-zealous removal attempts of the spark plug end of the wire. Once the wire moves inside the boot, it's going to have to be replaced.

The key is that you should grasp ONLY the square portion of the boot (do not pull, tweak or even hold the wire portion when removing or installing wires onto spark plugs).

[thommo59]

What is the correct part number for the most up to date set?

[EuropeanAM]

8M0159115 (based on the OP'ers engine).

[thommo59]

Thank you that’s the number on the ones I bought

[22R]

Fouled plugs on a new 4 stroke engine with only 80 hrs ?? Wow I have yet to foul a plug on my 29 year old fire breathing smoke belching adrenaline pumping duece stroke .....Ehh progress huh.
Best of luck hope you get it fixed.


22R

[EuropeanAM]

But let's stick to the engine covered in the thread.

[1Holeshot]

What would I need to do to get my spark plug wires replaced under warranty? See S/N in my sig below.

What about fly wheel?

[EuropeanAM]

A dealer would need to find a DEFECT in your plug wires.

[1Holeshot]

A dealer would need to find a DEFECT in your plug wires.

Thank you Don.

Not too much longer before my next maintenance and I will ask dealer to check wires and flywheel.

[EuropeanAM]

[knopf]

Partially true- Partially false.

Most of the problems did stem from over-zealous removal attempts of the spark plug end of the wire. Once the wire moves inside the boot, it's going to have to be replaced.

The key is that you should grasp ONLY the square portion of the boot (do not pull, tweak or even hold the wire portion when removing or installing wires onto spark plugs).

Thanks Don. That is what I did. I rotated the wires several times to break the contact point and then pulled using only the large square part of the wire.