Minto 170

[Lance Van Nostrand]

Brian,
Interesting ying and yang here on engines.  2 stroke tuning problems don't arise that often, and last week you couldn't get a word in edgewise for all the YS blues!!

it's not common that the midrange would be lean, especially on the full Mintor setup.  I haven't seen that.  The pipe is an essential part of balancing the mixture in a 2 stroke and I know the Mintor pipe produces an even mixture, even if not top power.  Please check the engine cooling.  This can significantly affect performance.  Fly with the cowl off for comparison.  If there's a difference, then maybe you need more exit area, or another hole in the bottom of the chin cowl behind the engine.  
    If the engine is lean in midrange it will get very hot in the air and this is not good.  I've seen one engine where the owner decreased teh pump pressure so much that it went lean in midrange and he nearly burned it up.  Are you still at the factory pump setting?  If you've decreased the pump pressure, then increase it again.  If you are flying 10%, then increase to 15%.  Some engines of early vintage prefer a bit more nitro.  Another way to richen the midrange is to shorten the header.  This is not my first suggestion though, because the factory setup works fine, however I've experimented with doing this and found that the 170 will gain a lot more power on a slightly shorter pipe at the expense of a richer midrange.  Normally, this is a bad thing.
   I have had good luck with setting everything a slight bit rich on the ground.  This is not because I'm expecting it to lean out in the air, but because I think it helps the engine slow down faster and it doesnt' spool up on downlines.  

--Lance
  ----- Original Message ----- 
  From: Lena Billings 
  To: discussion at nsrca.org 
  Sent: Friday, June 11, 2004 9:27 AM
  Subject: Minto 170


  Oh, I forgot to ask if anyone has any good tips on running the Mintor 170 with Mintor header and pipe, I have been careful as to not tear this one up yet and refuse to fly her until she is right as possible, mid range seems lean on the ground but idle is good and high end can be set very rich with no problem so pump seems ok. Also does anyone know of a air filter that fits these?

  Thanks
  Brian Billings
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