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<DIV>RE: OS 1.40 rear bearing rust - by Bax OS Factory Engine Support<BR>~~~~~~~~~~~~~~<BR><BR>On a Pattern engine, being flown in a Pattern airplane, 100 flights would be about normal for bearing wear. A competitive Pattern flyer will need to change out the bearings 1-2 times per flying season (depending upon how much practice time is spent).<BR><BR>Corrosion is caused by model fuel. The alcohol in the fuel absorbs water. Synthetic oils are slightly acidic and are not corrosion preventers, they are lubricants. The two are not necessarily the same. Some spent combustion products always work themselves into the lower-end of the engine and they are slightly acidic. This encourages corrosion by providing an electrolyte between the dissimilar metals in the engine (aluminum and steel).<BR><BR>You need to run the engine dry of fuel at the end of each flying session, and then flood the engine with an after-run product. One of the hobby blends of after run oil, Marvel Mystery Oil, automatic transmission fluid, non-graphite gun oil, a good coating-type machine tool oil...all will work well.<BR><BR>If the fuel has more than 25%-50% of the oil blend being castor oil, you'll also get significant corrosion protection. Engines run on all-castor fuels don't get much corrosion, but you do have to clean the engine to remove the varnish buildup from the castor oil. It also will become gummy when it sits for a long time. <BR><BR><BR>----------- End of Message -------------<BR><BR>The message can be located at:<BR><BR>http://www.rcuniverse.com/forum/fb.asp?m=1802477<BR><BR><BR>AOL users click <A title=http://www.rcuniverse.com/forum/fb.asp?m=1802477 href="http://www.rcuniverse.com/forum/fb.asp?m=1802477">here</A> to view the thread<BR></DIV>
<DIV>Chris Dansereau Sr.</DIV>
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