Best technique for clearing a fouled plug

[awmuhs]

Hello Paul,

I am not very scientific. I take the RPM up to at least 2200 and lean until I get a little rough then slightly enrich the mixture. Wait a minute or two and then do a mag check 1700RPM. Works every time.

I wonder if the gap in your plugs are set right. Is it the same plug every time? Are the EGT temps pretty tight together when you are leaned in cruise? I am thinking that maybe you have to much fuel going to one cylinder. Our friend Mel juggled his fuel injection nozzles to help him match the flows and narrow the EGT spread. Which in your case might prevent fouling a plug

Who did you use to inspect your airplane? I will need someone in a couple months.

Good Luck

[Don]

Originally Posted by Walt

Well you may not like this but.... the only real way to clean your plugs are to take them out and do the job

Walt, I'm not doubting you - and your advice, albeit occasionally pithy, is usually spot on...so I'm hoping you can explain a bit more.

In my somewhat limited experience, leaning on the ground for a minute at 1800 RPN has always taken care of a failed mag check due to a fouled plug. So I assumed (ah there's that word) that I was returning the plug to operational condition. One plane I have has 2 mags and the other one mag and one EI with auto plugs. I've had fouling on both but only when I don't lean properly on the ground, which is fairly rare. I'd guess I've had 3 or 4 instances of needing to lean after a run up in the past 3 years.

Thanks - and I'm not challenging you, just looking for a bit more depth to your answer.

[turbo]

when i had this issue years ago with massive gap plugs, use iridium's now, a climb to 1,500 ' and then a mag check always turned up good. good luck.

[Walt]

Originally Posted by Don

Walt, I'm not doubting you - and your advice, albeit occasionally pithy, is usually spot on...so I'm hoping you can explain a bit more.

In my somewhat limited experience, leaning on the ground for a minute at 1800 RPN has always taken care of a failed mag check due to a fouled plug. So I assumed (ah there's that word) that I was returning the plug to operational condition. One plane I have has 2 mags and the other one mag and one EI with auto plugs. I've had fouling on both but only when I don't lean properly on the ground, which is fairly rare. I'd guess I've had 3 or 4 instances of needing to lean after a run up in the past 3 years.

Thanks - and I'm not challenging you, just looking for a bit more depth to your answer.

"Occasionally" a lone piece of carbon/lead may short the small gap of the aircraft plug but not usually, 95% of what I see is heavy lead fouling in the bottom plugs which can only be properly cleaned by removal of the plug and a good mechanical cleaning. The small gap on aircraft plugs make them much more susceptible to "fouling" (electrode shorting) than the big gap on the auto plugs. Hard running at lean mixtures (high temp) may clear the "shorted" plug but its usually a temporary fix.

[GalinHdz]

Originally Posted by Walt

Well you may not like this but.... the only real way to clean your plugs are to take them out and do the job

Or replace them.