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<DIV><FONT face=Arial size=2>I ran into a little snag while starting a fairly
new Webra 1.60 today. It has about 30 flights and has been running well, with
the exception of the previous two flights where it suddenly didn't want to stay
lit after starting, just prior to takeoff. Trouble free during those two
flights though, this with a replacement OS type F plug just in
case.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Back to the problem today, while starting, there
was suddenly a great deal of binding while turning the prop. I pulled the
prop and discovered that the thrust washer was scraping against the crankcase
and had produced a couple of fine shavings. Also noticed the dreaded
metal/grease paste from previous wearing, all around the end of the case and
behind the thrust washer. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I don't think any shavings got into the front
bearing, since it never ran once I noticed the binding, but it's a fairly sure
bet that this has been making some contact when the starter has previously been
in use, so some amount of crud has probably passed through. Compression is
still great and there is no visible sign of wear to the liner or piston, so my
first question is about whether to tear it all down to clean it and replace
bearings just in case. The second and more pressing question is why did
this happen in the first place? Is it possible that over tightening the
prop nut will force the thrust washer far enough back to allow contact under the
load of a starter? Is it more likely that there is a main bearnig wear
problem allowing the contact? There is very little run out to the crank
when pushed/pulled from the front, but should there be any that is detectable
this way?</FONT></DIV>
<DIV><FONT face=Arial size=2>Thanks</FONT></DIV>
<DIV><FONT face=Arial size=2>Ed</FONT></DIV></BODY></HTML>