Hello, Ken...
 
 KE> I have a question that I have asked so many and everyone at the
 KE> local flying field here has a different answer.  First, my question,
 KE> is there guide lines that a person could go by when trying to decide
 KE> what propeller to use with a particular size engine???  I have bought
 
 There are good guidelines for choosing the proper propeller for an engine,
 I'm surprised that you found so many different answers.  These guides can
 be found in many places but probably the most easily accessible is the
 Tower Hobbies annual catalog which shows both props and engine mounts for
 various sized engines.  The catalog is free for a telephone call.
 KE> several used engines and I cannot figure out what is the right prop
 KE> to use and which is wrong.  I have the following types:  OS .10,
 KE> TIGER .40, K & B .61, and a .25 .......    If someone could tell me
 KE> what the proper props are to use (and what makes one different from
 KE> another) I would greatly apprecaite it....
 Propellers are sized with two numbers which describe the length and the
 pitch - for example, a 10-6 prop will be 10" in length and 6" in pitch
 (pitch is the distance the prop will travel forward in one revolution if
 it were 100% efficient).  Here's Tower's suggestions for your engines:
 OS 10 - use a 7-4; Tiger 40 - use a 10-6; K&B 61 - use a 11-7; K&B 25 - 
 use a 9-6.  Good luck, let us hear from you again.  TTYL - Roger
... Catch the Blue Wave!
--- Blue Wave/RA v2.12 [NR]
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