I guess I asked for that but they haven't seen any problem with them in PA46.And they do a lot Of them.
Mike Busch of Savvy has an excellent webinar on plugs and discusses the Champion problems. If you already know all about plugs skip to 41 minutes for the issues.
Someone started a Class Action against Champion, last year
I’ve been struggling with the sensation that all was not quite as it should be with my engine when LOP. At first it was an eery feeling more than anything tangible, but I there was sometimes some light misfiring which went away when I went ROP.
Then in February I had problems starting. I pulled the plugs, cleaned and gapped them, put them back in and the engine started. I noted that the plugs had the straight slot in the bottom of the plug well, which raised a faint alarm bell to the Champion resistance problem. On a subsequent flight, during run-up a cylinder shut down when running on a single mag. And then I had another mag test issue at Bergerac. I performed an in-flight mag check and discovered that the engine misfired on one mag.
After having inspected and tested the wiring harness, studied the engine data, looked up exactly what plugs from Champion were affected by the resistor issue (all with a slotted screw in the well) I decided that the problem had to be with the spark plugs which had about 250 hrs on them. So I ordered a fresh set of Tempest massive electrode plugs and spent a day replacing the Champion plugs.
After having pulled all of the Champion plugs, I cleaned them up some in order to get good contact for the ohmmeter probes and measured the resistance:
I have only flown 80 minutes with the new plugs, but so far so good. A high-altitude flight will provide the definitive answer…
New Tempest plugs made my engine markedly smoother, even as the previous Champion fine-wires passed the useless bomb test.
All of my plugs passed the bomb test.
All of the new Tempest plugs had a resistance between 1 and 1,3 kΩ
SteveN wrote:
Spark Plug webinar
And the “wisdom” from this article is that you should replace all spark-plugs over 5000 Ω
I’m measuring my spark-plugs at 50h inspection, after cleaning, (blasting), and if over 5KΩ, I just replace them.
Consider this as a cheap insurance
Now here is coming an additional question. The spark-plug have carbon bit, and this is what we are measuring.
This carbon stub can be easily changed. Is there a place on the earth where you can buy it ?
In this way the spark-plug life itself can be extended if the bomb test is passed.
The resistor is a piece of silicon carbide, which is a resistor whose value varies according to the voltage across it. It’s a bit pointless; a fixed-value resistor works just fine. While it may be replaceable, the whole mechanism which holds it in place is flimsy. Take one of the plugs apart and you will see.
The answer is to use Tempest spark plugs.