<VV> Exhaust Temps

[Brown, Douglas T CIV NAVAIR DEPT]

I just did a tune up on my 140 and noticed the sound of the left exhaust was not as pronounced as the right.  I can only describe it as wispy or feathery, as if there were a slight leak, but there isn't.  So I put my hand behind the pipe to feel the output.  The left one was not as hot as the right.  The pulse is even, but the temperature is considerably lower.  
When I did my valve adjustment after a recent rebuild, I did them cold, and only turned the nuts 1/4 turn past contact.  Could I have valves on that side that aren't opening all the way (or not closing)?  Has anyone experienced a similar difference in exhaust tone and temp?  Power seems normal, although my last 140 drive was years ago, so I'm guessing.

Toby Brown
San Diego CC