Tempest Spark Plug Issue

[tomn]

I just changed my plugs with a new set of Tempest while the plane was down for a prop overhaul. After installing the prop, we dynamically balanced it running the motor for only about five minutes. That run included three 2400 rpm run ups for only 10-15 seconds while the computer was taking its readings. After dynamically balancing the prop, we pulled the top plugs to check the timing and found this bad plug. I immediately contacted Tempest and sent them the plug so they could determine the cause - here's what we learned.

What you see in the picture is a thin metal round gasket ring that is inserted between the ceramic insulator and the plug housing during assembly before being pressed together. Somehow two rings had been inserted instead of one and the second apparently popped out during the prop balancing run ups. It is a complete ring that could not be removed by pulling on it since the electrodes were blocking its movement. 

I have talked with Tempest several times since this occurred and must say that they have been great to deal with. They contacted me immediately very early the next morning after sending them an email the night before with pictures of the plug. They sent me a replacement plug right away and kept me informed about what they found when they looked at the plug. They believe that this was an isolated incident and are looking further into the issue and the assembly process. Its great to have a manufacturer that provides this level of support for their product.

I felt it was important to pass this information along. It would be a good idea for anyone installing plugs to look at them carefully for anything that does not look right. I do not know if you can see if there are two ring gaskets installed as happened here, but you can see the one ring down inside the plug if you look carefully.

 

Tom

[Andy95W]

Nice catch!

Makes you wonder, if Champion had been that responsive to a problem, there wouldn't be so many Champion sparkplugs being thrown in the trash right now,

[carusoam]

Tom,

Great customer communication with the vendor!

Fortunately, the tiny foreign object wasn't released in the cylinder.

Thanks for sharing.

Best regards,

-a-

[MooneyBob]

You should buy a lottery ticket right now.

[chrisk]

Every company has quality issues.  The real question is how often they have quality issues, and how they respond to those issues.  I've not heard of this before on Tempest plugs, so I assume their quality control is generally good.  And it sounds like they handled this issue well.  --My existing set of plugs are Tempests.  My next set will be Tempest also.

[tomn]

I had the bad resistor Champions that I replaced with these Tempest and the plane is running much better.  I used Tempest plugs in my Mooney as well with great results.  My next set will be Tempest - I use their oil filters as well.