I second that.

What John Deakin said can be basically summarised in two parts:

1. Anytime the power setting is above 75%, use full rich. Check the
fuel flow and make sure it's rich enough for the engine and power
output.

2. Anytime the power setting is below 75%, lean the mixture
REGARDLESS OF THE ALTITUDE. The lower the power setting, the more
aggressive the mixture should be leaned. On the ground, the mixture
should be leaned to the point that the engine barely runs. For engine
that has good mixture distribution on all cylinders, use LOP
operation.

I follow these rule of thumb and my engine couldn't be happier. John
Deakin's article taught me that the decision of *whether to lean the
mixture or not* has nothing to do with altitude, only with power
setting. The only thing varies with desity altitude is how much
mixture control you need to pull out to achieve a specific mixture
setting.

I wish they could teach this in primary training and we can all be
spared from all the fouled plugs.




(Michael) wrote in message . com...


Actually, most of what John Deakin writes over on AvWeb on the topic
is totally unoriginal - and very correct. And you would be amazed how
often it is marketing rather than engineering that writes operating
manuals - in any industry.

Michael