Piston power loss
 

We operate a Slinsby Firefly T67B with a 116Hp lycoming engine. We have experienced complete loss of power at Approx 2/2500 ft when the electric fuel pump is turned off. A new mechanical pump has been fitted and today the problem re-occurred. it can't be re-created on the ground and all pre-flight checks are OK. Any ideas appreciated, could it be pressure related in any way?:confused:

Had something similar years ago. The plunger that operates the engine driven pump had been damaged on a pump installation and wasn't actually operating the pump.

With the pump off and a mirror you could see that the rear cover where the plunger ran was cracked allowing the plunger to fall off the end of the pump operating arm.

Thanks, that sounds worth a look, i'll have to get it back to our engineers this week. Its certainly a new one to me!

Should have said that this was on an O-540 in a 172RG.

Should have said that this was on an O-540 in a 172RG.
Hope it isn't this as a new rearcover is the fix!!!!!