spark plugs

My engine, a lycoming O-540, is running a bit rough around ~1700 RPM. I've had this issue before and MX replaced all 12 spark plugs and everything was better. This time around it seems a bit worse and the mag checks show a drop of 175-200 RPM. On both the left and right mags it runs a bit rough...

I have 5 new-in-box Tempest UREM37BY spark plugs. They are still in the sealed tubes with copper gaskets. I purchased these from A/C Spruce over the past year or two so I'd have spares during my trips and at annual. No fouling with the extended massive electrode. A/C Spruce sells them for...

Reading the issues, dealing with funny running engines, did some more searching and LO AND BEHOLD... search for the Champion industrial spark plug catalog from 2012, on page four they describe the issue, and explain they only use fired in resistors for longer life. The chart is resistance...

First annual with new to me 182 with a carbureted o-520 and 7 out of 12 spark plugs were replaced due to wear beyond spec (pre-buy last october did not find or mention this as a potential issue and they were looked at during pre-buy). I have worked on many auto/small/farm engines and know how...