I own a Cessna 140A and it is equipped with a single cylinder Westach EGT that is not working. I am uncertain if it is the probe or the guage but I purchased a TSO'd new guage/probe for about $150.00.

I recently watched Mr. Busch's Webinar on EGT/CHT (and I remembered a key learning that went something like: an EGT is good for diagnosing engine problems but a CHT is better for determining mixture and proper leaning.)

So, my C-90 has less than 150 hours since overhaul and I want it to last. I rely on those who know more than I. I understand the concept of leaning, but apparently the EGT will be of little help. I have erred on the safe side (I thought) by running full rich while flying (typically at 3000' or so MSL).

So here are my questions:

1. Would you recommend a 4 cylinder EGT/CHT replacement guage for the single cylinder EGT? Is it cost effective?
2. Keep the single EGT? and lean the motor until it runs rough than en-rich the mixture until it runs smooth? (but avoid the little extra)?
3. Other?

Thanks,

Daniel

Thanks