Bill,

When you write "my old carb was shot and put on a spare they 
had and it supposedly ran fine. It has been doing well for about the 
last 4 hours I've flown it since the annual".

I wonder whether the carburetor is a Stromberg.

If so, the fuel level might be adjusted according to the manual. 
The normal adjusted carburetor can lead to fuel starvation in a nose high 
attitude at full power, leading to a total power loss.
The power comes back almost immediately when lowering the nose that allows the 
fuel level to reach the nozzle enough to provide a rich enough mixture.

One can prevent this behavior by applying carburetor heat, even on take off . 
The heat enriches the mixture.

I experienced this kind of symptom myself, resulting in a total power loss on a 
steep climbout after take off.

I lowered the nose in preparation for an off-site landing straight ahead, but 
the engine caught on almost instantly with the lowered nose.

Then I started some experiments at higher altitude with the runway in gliding 
distance. I could "extinguish" the engine by holding the nose up high at full 
power - just like that - lowered the nose and the engine started running again.
Did the same with carb-heat on and nothing happened. Engine keeps running.
The fix is to adjust the float level a bit higher. That way the main nozzle 
does not run out of gas so to say.

The problem might be elsewhere, but the only new thing your engine has is the 
carburetor and I would check there first.

Hartmut






  ----- Original Message ----- 
  From: wbuhles 
  To: [email protected] 
  Sent: Wednesday, May 21, 2008 9:29 PM
  Subject: [ercoupe-tech] Power failure on take off


  Hi Everyone;

  Had the time of my life last Friday. Just had my plane come out of 
  annual where they found my old carb was shot and put on a spare they 
  had and it supposedly ran fine. It has been doing well for about the 
  last 4 hours I've flown it since the annual. During the annual they 
  went through everything forward of the firewall and even had the 
  engine off. All short of an overhaul. Well on Friday AM I loaded it 
  up with full fuel and my suitcase and was going to fly from my home 
  base at Yolo County, CA to Lompoc (KLPC), about 270 miles. 

  Started up, taxied out, did run up and everything was fine, and then 
  sat for awhile as two Bonanza's were doing touch and go's. So the 
  engine was well warmed up. Started the take off roll and the output 
  was normal, about 2200 rpm, felt OK, so I rotated and was about 50 
  feet in the air when the engine power abruptly dropped to idle, then 
  caught again for 2 sec, then dropped again. I pulled back the 
  throttle and put the nose down and landed, a bit hard because I 
  didn't have a lot airspeed with which to finese, but intact. Luckily 
  we have a long strip and there was plenty of runway still in front of 
  me. Taxied back, put plane in hangar, drove to Lompoc.

  Before I put it away I did a static run up for about 30 seconds to 
  max rpm and all was normal on either mag, no cough nor sputter, 
  running smoothly. It is hangared, we have had no damp weather at all 
  this time of year, and the tanks were full. I did not drain the 
  gascolator sump in the engine compartment before I left.

  Thank goodness a past instructor had pulled the throttle on me once 
  at about 100 feet and it was my instinct to lower the nose quickly. 
  Likely saved my butt. Any comments or ideas on what it might be? I am 
  thinking fuel contamination of some sort. One clue, before the annual 
  the plane would start after about 4 pushes on the primer, and now it 
  takes 8 or 10 pushes on the primer before it will catch and start. 
  Cannot figure what might be causing that, but I know you guys will.

  Thank you in advance. 

  Bill Buhles
  N94157, 415C



   

Reply via email to