RPM drop during climb out
   I experianced this problem last year with my coupe
C85 with Stromberg
Keep in mind, My A&P also happens to be my CFI
 It developed a RPM drop of about 300 during climb out but as soon as leveled 
out engine regained lost power  
  First reared its head during instruction and on about my 6th touch and go it 
showed up 
* got back on the ground safely really quick 

  Note:  Very High pucker factor when it first happened.

  We proceded checking the following locations for the problem.
checked Fuel flow to carb / fuel lines ect.   no problems found
checked carb float setting and clean  cked ok 
engine specs such as compression  checked ok
looked at plug wires, they looked ok but changed anyway
checked mags for output  cked ok 
  He thought he had correcteds as his solo test flights showed 
 no RPM drop. (He weighs approx 150)
Then we both went up together and dang their it was AGAIN 
 
  Sent carb to Aircraft Systems in Rockford IL to do
 detail inspect/rebuild.
As soon as they opened carb the tech knew what our problem was
and his test proved right.
  Needle in carb had neoprene tip, it had expanded due to age and
 or long term reaction to fuel
   Test results as I understand
  Flow past needle was checked and found to be .030 
Tech mentioned it is to be at a minimum .048 
  So during take off (Climb out) it was fuel starvation,  engine not getting 
required fuel flow.
  
  New stainless tip in carb
  Problem solved.

   Kevin N2583H   (DVN)



Reply via email to