If you have an engine monitor, you can do a mag check looking at the EGTs, if you have one fouled plug, the EGT for that cylinder will typically rise faster than the others. I look mainly at EGTs when doing my mag check on my J. I want to see a slow and equal rise of all EGTs.

champion has had problems with plugs going high resistance. i forget the cutoff, but mine were off the charts for resistance. i had 3 of them that were high resistance when I checked when I found out about the problem. it was still running decently. now it runs better. this is one reason that I have gone to using tempest plugs. unless your plug wires are misrouted, it is normal to run half bottom plugs (one side) and half of the top plugs (other side) from one magneto. btw, that is cylinder 2 on the front left cylinder 1 is front right.

Good find!

I’m glad it was an easy fix. Your rain looks a lot like the rain we have here in Oregon. Have fun flying.

When I was an auto and motorcycle mechanic years ago, I hated Champion spark plugs..

One thing to note, you said your left mag runs the bottom plugs, typically mags are wired so one runs top on one side and bottom on the other. Take a look at how yours are wired. FWIW, your left bank is 2 (front) & 4 (rear), right is 1 (front) & 3 ( rear) cylinders. I wouldn't necessarily run fine wires unless you fly at high altitude most of the time. That's where they shine. That said, look into REM40E plugs vice 38's, they burn hotter and help with lead fouling some.

Two points, when inspecting a plug look carefully inside the barrel looking for a crack in ceramic, if found, throw the plug away. If the the ceramic comes apart in flight fragments will destroy the other plug in cylinder. The plane will not fly on 3 cylinders. Having said that, if a plug is dropped onto a hard surface, throw it away ( see above).

Just a point of explanation. On meter resistance settings, OL stands for Open Loop.

welcome to Champion plugs, if you look down into the "cigarette well" you'll see what looks like a screwdriver slot, if this is the case take the plugs and toss them in the garbage. Champion will never admit they had a resistance issue, but if you do some simple searches on the internet you'll see Champion tests as either super high resistance or completely open. Their new design plugs do not have this problem, or just use Tempest, they are as good or better and don't have resistance problems.

Good find. If you save your old plugs there’s a company that redoes them for $3 each, Mike Busch talks about doing that. This would give you spare plugs on hand too.

Each mag runs the top plugs on one side and the bottom on the other side

I hate how many screws are on the cowling. Aviation plugs look bad because of all the lead. It shouldn't be excessively oily and shouldn't have any "clinkers" in there. Clinkers are just the lead balls. My plug on that side is a bit oily too. I think I have some blow by that I'm gonna get checked at my annual. The Mags power a bottom set and a top set on the opposite side. I believe 5K ohms is the high end, but I'd also check plugs in a plug testing machine. They allow you to see the plug to arc under air pressure to see if you're getting a good spark. Front Right cylinder is #1 and Front Left is #2.

Do not put a whole lot of anti seize on the plugs, as if any gets inside the cylinder it will cause detonation

The beginning I was thinking I hope those are Tekton tools

champion make a sparkplug chart that you can hold the plug and match what the issue or non-issue you are seeing. I prefer fine wire. I replaced all my plugs last annual just to make sure my performance was higher. mass electrodes are expensive so I just said fine wire is only a bit more but last so much longer with a bolder spark.

Take the other plug out of the same cylinder that the wet plug was in and inspect it. If it is also wet or shows signs of excessive oil or foiling you could have a mechanical issue with that cylinder. Hopefully not, hopefully it was just a bad plug, but if you do it will be much cheaper to find it now before it causes damage, not to mention if it does it while in the air.

I’ve never seen aviation spark plugs before, interesting. How many does that 4 cyl have, 8? 4? Good luck friend.

Do you have an engine monitor installed?

Go with Bosch Platinums much better.