Weasel
Well Known Member
I have a love for "how things work" that began when I was little. If something is not working right I not only want to fix it but I would like to know what caused it and why it is causing the problem prior to fixing it as opposed to just trying this or that to "see" if that is the problem.
On a recent flight the engine on the -10 started running noticeably rougher.
I waited a little and it changed from intermittently rough to consistently rough.
I had several things immediately run through my mind.
The first was a slightly restricted "plugged" fuel injector. I began analyzing the data on the Dynon Skyview and noticed the EGT on Cyl #5 was about 100 deg F. higher than the average temperature on the rest of the cyl's.
However I was running LOP so if that injector was restricted I would have expected to see it running a lot cooler than the rest of them but it was not.![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
So the next step was to think about the ignition.
I switched from BOTH (magneto and Lightspeed) to Mag.
When I did this the engine ran rougher and the EGT for #5 started dropping like a rock. Ahah. Switched to Lightspeed and the roughness went away.
I was then sure that the problem was in the Mag, Mag Harness, or the sparkplug connected to the mag.
When I got home I pulled the plugs and there it was simple as pie!
On a recent flight the engine on the -10 started running noticeably rougher.
I waited a little and it changed from intermittently rough to consistently rough.
I had several things immediately run through my mind.
The first was a slightly restricted "plugged" fuel injector. I began analyzing the data on the Dynon Skyview and noticed the EGT on Cyl #5 was about 100 deg F. higher than the average temperature on the rest of the cyl's.
However I was running LOP so if that injector was restricted I would have expected to see it running a lot cooler than the rest of them but it was not.
So the next step was to think about the ignition.
I switched from BOTH (magneto and Lightspeed) to Mag.
When I did this the engine ran rougher and the EGT for #5 started dropping like a rock. Ahah. Switched to Lightspeed and the roughness went away.
I was then sure that the problem was in the Mag, Mag Harness, or the sparkplug connected to the mag.
When I got home I pulled the plugs and there it was simple as pie!
![Rough1.png](/proxy.php?image=https%3A%2F%2Flh3.googleusercontent.com%2F-ZIqAKmqhvrs%2FUgaJTu_utzI%2FAAAAAAAAClI%2FLmqE5oKHT6c%2Fs800%2FRough1.png&hash=da1b025b696b33efc5133eeb12aff7b2)
![Rough.png](/proxy.php?image=https%3A%2F%2Flh5.googleusercontent.com%2F-e6F7dF6zfko%2FUgaJTRplvuI%2FAAAAAAAAClI%2FggGqkMUyRbc%2Fs800%2FRough.png&hash=85153dbbd4827d7dac58d3d4ed86eede)
![20130806_162351.jpg](/proxy.php?image=https%3A%2F%2Flh6.googleusercontent.com%2F-G_sWwwTlEYY%2FUgT6BWMU58I%2FAAAAAAAACjY%2FZMMtUzliF3U%2Fs800%2F20130806_162351.jpg&hash=33eb8a9e23382401e36776e2d363b3c9)
![20130806_162500.jpg](/proxy.php?image=https%3A%2F%2Flh3.googleusercontent.com%2F-E3EiHRIhFLg%2FUgT6M6Cf_VI%2FAAAAAAAACjg%2Fb2jxeRTT824%2Fs800%2F20130806_162500.jpg&hash=66dd8d7b3813e300586962aabaacfb88)