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General control line discussion => Open Forum => Topic started by: Bootlegger on March 15, 2007, 10:45:23 AM

Title: ...venturi size...
Post by: Bootlegger on March 15, 2007, 10:45:23 AM

 Mornin fellow's,
  I have a Ringmaster that is powered by an OS 25 FP, with a .250 venturi, I am lookin for suggestions as to what size venturi will be better.
  The fuel is Powermaster 5% with 22% oil (half & half) a Thunderbolt long plug w/idlebar and a 9x5 APC prop line length is 58' eyelet to eyelet.
  Probably around 10,200 or there about  R P M range...
  Thanks again Sparkey for this site... D>K #^ #^

Title: Re: ...venturi size...
Post by: Bill Little on March 15, 2007, 12:38:53 PM

Hi Gil,

What do you want it to do different?  Have you tried it?  Not trying to be a smart alec, just not sure of the question.............

Bill <><

Title: Re: ...venturi size...
Post by: Steve Holt on March 15, 2007, 03:26:29 PM

The FP25 on my ARF Streak has the same venturi, an OS needle valve assembly, and the OS 2030 muffler.  Tank is a 3 oz Hayes clunk on muffler pressure.  On a 9X4 APC prop I set about 12,500 rpm on the ground.  Works well here in Tucson on 60' lines.  Fuel is 10% nito, 22% oil (half castor and half syn.).  I have used the same set-up on a Ringmaster with good results.  If it is too fast on 60' lines, try 63'.
Steve