2018 250 ProXS 4S misfire, no faults

[bassketcase05]

Serial # 2B529823
This issues started this spring after sitting all winter in my garage, and appeared to be intermittent, progressing to be constantly running rough, but occasionally running good at WOT. I had it checked at dealer @ two months ago, and it was diagnosed as the #1 cylinder was misfiring and the spark plug wire was pulling out of the boot...plug wires were on backorder, so an attempt to correct it seemed to work for at least one trip on the water...fast forward to this past weekend and new plug wires were installed, check the motor on the muffs and it appeared to be good. I took it out yesterday and its back to running like a turd. What would be the next thing to look for? Thanks in advance.

[Fishysam]

What about the plugs them selves? Have they been replaced since the wires were?

[bassketcase05]

Plugs were checked for proper gap, etc. But not replaced.

[21xTriton05]

Replace the plugs and your issue will likely go away. I've had a lot of fouled plugs on these 2018/19's

[bassketcase05]

Replace the plugs and your issue will likely go away. I've had a lot of fouled plugs on these 2018/19's

Was it a specific cylinder that had plugs fouling or all? I only have @ 95hrs on this motor.

[SilverFox579]

Check spark plug service interval language in your owner's manual, it might say x hours or annual, whichever comes first.

[Customsilverado]

Did changing the plugs on this motor solve your problem?

[EuropeanAM]

Might also be wise to have the dealer do a Cylinder Misfire Test at various RPM's. And inspect fuel injector harnesses (hidden under plastic covers) for any signs of abrasion or pinched wires (such as #7, for instance).