Expected rpm on 120ac

[Verne Koester]

Del,
On a straight-up rebuild with all else being equal, I'd view the carb spitting as the key symptom. Sounds like the timing might be off. I'd double-check the cam and make sure it's not off a tooth.

Verne
  ----- Original Message ----- 
  From: Del Rykert 
  To: discussion at nsrca.org 
  Sent: Wednesday, July 02, 2003 10:35 PM
  Subject: Expected rpm on 120ac


  Would appreciate opinions.

  I have a YS 120ac that has been a strong runner in the past. Would turn a 15x12 apc 8300-8400 on 25% powermaster. It was rebuilt last season but never run till this season. It was giving me fits at Hamburg contest and taching is only showing 7800 to 8000. Needle 1 1/4 out. Seems to spit more fuel out of air inlet than I used to see. 

  My question being am I being unrealistic expecting it to continue to give me 8300-8400 on that prop & fuel. Valves check at 002 piston TDC cold. Good seal in valves. Don't feel any drag from bearings but I replaced bearings last time and was surprised on ratty they were after dis-assembly. Might my bearings be the culprit and next item to explore?

  TIA for all who reply.

    If you choose to reply off list...   drykert at rochester.rr.com 

       Del K. Rykert
       AMA - 8928 
       NSRCA - 473
       Kb2joi - General 



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