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<DIV>I am not sure why this kind of argument surfaces every couple years.....but it does. In my experience, whatever procedure works for you after a session then use that. As Tom mentioned, in humid climes you might want to use the after run. In drier climes you can get away with what Mike and Wayne do. I lived in hot, humid FLA for 16 years and learned to use castor as the after run and never had bearing problems. When I moved to Jersey a couple years ago (which is also a humid place in the summer) I didn't follow the method as religiously as in FLA and had a bearing failure in my W160 after less than 100 runs. Lesson learned.</DIV>
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<DIV>The take away is that the newer folks among us should pay attention to what the more experienced are doing in THEIR area and follow that technique. </DIV>
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<DIV>Running the engine rich throughout the range is a major reason bearings last a long time and conversely, lean runs are bearings killers regardless of the afterrun method one uses. Rich running throughout requires a properly tuned set-up for 2 strokes on pipes. In my view, 4 strokes generally have had comparatively few bearing problems because they won't run well lean but run fine at richer settings.</DIV>
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<DIV>And BTW, as Karl implies below, higher nitro requires a more open needle which, among other things, forces more oil through the engine per cycle</DIV>
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<DIV>MattK</DIV>
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<DIV>In a message dated 5/9/2007 5:50:38 PM Eastern Standard Time, kgamueller@rogers.com writes:</DIV>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid">
<DIV><FONT face=Arial size=2>I'm going to have to chime in here.</FONT></DIV>
<DIV><FONT face=Arial size=2>After running OS 160s for about 5 years ( 2 engines alternating )</FONT></DIV>
<DIV><FONT face=Arial size=2>and changing to Powermaster 20/20 and 20/30 I have had no</FONT></DIV>
<DIV><FONT face=Arial size=2>problems with rust whatsoever. During the season of high humidity</FONT></DIV>
<DIV><FONT face=Arial size=2>I will run the engines dry after a flying session. Last fall I did that</FONT></DIV>
<DIV><FONT face=Arial size=2>before hanging the planes up for the winter with the nose down</FONT></DIV>
<DIV><FONT face=Arial size=2>and that is all. No after run oil of any kind. When I inspected the</FONT></DIV>
<DIV><FONT face=Arial size=2>2 engines this spring there was not a sign of rust to be found.</FONT></DIV>
<DIV><FONT face=Arial size=2>Still running the original bearings as well. Now I did find some wear</FONT></DIV>
<DIV><FONT face=Arial size=2>on the rear bearing on one engine and will put a new set of just</FONT></DIV>
<DIV><FONT face=Arial size=2>standard bearings in it. </FONT></DIV>
<DIV><FONT face=Arial><FONT size=2>The exhaust residue is</FONT> <FONT size=2>always still on the pink side (color of the oil)</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2>and my engines have never run hot.</FONT></DIV>
<DIV><FONT face=Arial size=2>With running the higher nitro you would think that this would cause</FONT></DIV>
<DIV><FONT face=Arial size=2>more of a problem. But not so. I am very happy with the results</FONT></DIV>
<DIV><FONT face=Arial size=2>and will keep on using the fuel I am using now.</FONT></DIV>
<DIV><FONT size=2></FONT><FONT face=Arial></FONT> </DIV>
<DIV><FONT size=2><FONT face=Arial>Karl G. Mueller<BR></FONT><A title=mailto:kgamueller@rogers.com href="mailto:kgamueller@rogers.com"><FONT face=Arial>kgamueller@rogers.com</FONT></A></FONT></DIV></BLOCKQUOTE></DIV>
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