N6784N Posted April 30, 2010 Report Posted April 30, 2010 I was doing my runup today and my left mag was showing a pretty good drop in rpm's so i went to 2000 rpm's and leaned it out for a minute and brought it back to 1700 rpms to check the mag and it didnt work out too good for me. i did this 3 times with the same outcome actually the plane ran a bit rougher after. could this be a spark plug or is it more a mag problem? and does anybody know with a 1968 model c will i be able to install slick mags on it or wil i have to have the mag rebuilt if that is the problem? thnx for any info you guys can give me
140pilot Posted April 30, 2010 Report Posted April 30, 2010 We had it happen a couple times over the years and both times it was lead fouling of the plugs.
Mooney65E Posted May 1, 2010 Report Posted May 1, 2010 I'd be safe to say you have a mechanical tach and no multiprobe engine monitor. With an eng. monitor you'd see a drop on one cylinder when your engine runs rough. Clean the plugs on that cylinder and be on your way. With a digital tach, you get a red light on a failed mag and could change the the name of this thread to "mag problems I know". I'm not trying to sound like a smart *ss. I've been there. Got stranded at an airport with a ruff running engine not knowing if it was a mag or plug. No mechanic on the field...FBO closed...walk to town ... pay for an expensive hotel...wife not happy...miss a day of work...this starts to add up! Wasn't long before I spent money on a P-1000 Horizon digital tach. and a JPI EDM 800. Best of luck getting to the root of your problem.
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