Friday, October 12, 2007

Spark Plug rotation

Owner maintenance rules permit owners to remove, clean and reinstall spark plugs. Plugs are expensive at $25+ each, and they need to be treated with care. They also should be rotated in their firing positions to prevent eroding the electrodes in an irregular fashion.
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You need to exchange the # 1 cylinder plug with the # 4 cylinder plug and the # 2 with the # 3 if you want to make sure of the change in polarity. It is also a good idea to exchange positions - top to bottom - to ensure that a minimum of lead fouling accumulates.

Also, idle at less than 1200 RPM tends to lower the plug's nose temperature below 900 F causing the fuel's lead scavenging agents to be ineffective in preventing lead fouling. Remember, idle mixtures are overly rich anyway, adding to the problem of lead-fouling.

2 comments:

Michael Shaw said...

Hi Frank

You pose interesting questions at your blog. Should I be surprised that so few folks comment on "aviation matters"?

I guess our silence shows that pilots really want COPA, RAA, EAA, IAOPA, AOPA, etc. speak for them. Do pilots only get involved when they perceive a direct threat to their aviation activities?

All the best in your blogging--after all aviation does matter!

Thanks for the comments on my blog copa8.blogspot.com.

Mike

Anonymous said...

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