re: engine too lean?

["Robert W. Murphy" <rmurphy@domain.elided>]

This past weekend I pulled the spark plugs from my 90 Spider to check them 
(Splitfires w/ 25k miles).  The electrodes were covered with a very light 
brown, not quite white,  crust.  I brushed the plugs with a wire brush and 
checked the gaps (some had grown slightly) and put them back in for another 5k 
miles.  My question is:  does this very light brown crust indicate that the 
engine is running too lean or a little lean?  Should I richen the mixture some 
and if so, how?  The ignition is Motronic.  Shouldn't the computer make it's 
own adjustments?  Is the computer sensing something else and leaning the car 
out?  I have also noticed that the exhaust temp seems  to be high.  After 
running more than 30 minutes I cannot touch the tailpipe for more than a 
second or so, or I will get burned.  Is this normal?

Thanks in advanced for any help!

Rob Murphy
90 Spider
Coral Springs, FL

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